This research was financially supported by Ministry of Science and Technology, Taiwan (104-2514-S-009 -001, 104-2627-M-009-001 and 102-2311-B-009-004-MY3). We thank the National Nano Device Laboratories (NDL) for its valuable assistance during device fabrication and analysis.

1. Herstellung und Konservierung von pSNWFET Devices <ol><li> Vorrichtung Fabrication Hinweis: Die pSNWFET wurde unter Verwendung eines Seitenwandabstandshalter Technik wie zuvor 23,24 berichtet. <ol><li> Bereiten Sie die Gate-Dielektrikum-Schicht. <ol><li> Kappe mit einer 100 nm dicken thermischen Oxid (SiO 2) Schicht auf einem Si - Substrat durch das Naßoxidationsprozeß 25 mit (O 2 und H 2 Prozessgas bei 980 ° C für 4 h). </li><li> Ablagern einer 50 nm dicken Nitrid (Si 3 N 4) Schicht , die durch chemische Niederdruck - Dampfabscheidung unter Verwendung von (LPCVD) 25 bei 980 ° C für 4 Stunden. </li></ol></li><li> Abzuscheiden , einen 100-nm-dicke Tetraethylorthosilikat (TEOS) -Schicht durch LPCVD unter Verwendung von 25 bei 780 ° C für 4 Stunden. </li><li> Führen Standardlithographie unter Verwendung einer I-Line-Stepper das Oxid Dummy-Strukturen zu definieren. <ol><li> Bestreichen Sie die Waferoberfläche mit einer 830 nm dicken Fotolackschicht. </li><li> ichnsert ein Muster definierte Photomaske in das I-Line-Stepper. </li><li> Verarbeiten, um die Belichtung durch die I-Line-Stepper verwendet (Wellenlänge: 365 nm) bei einer Stärke von 1.980 J bei Raumtemperatur. </li><li> Entwickeln des Wafers in einem Entwickler für 5 min. </li><li> Führen Sie den isotropen Ätzprozess durch einen Standard mit induktiv gekoppeltem Plasma 25 Radierer mit HBr und Cl Plasmagas für 1 min. </li></ol></li><li> Abzuscheiden 100 nm dicke amorphe Silizium (α-Si) Schicht durch LPCVD 25 verwendet wird . </li><li> Durchführen eines Wärmebehandlungsschritt bei 600 ° C in N 2 -Umgebung für 24 h das α-Si in eine polykristalline Struktur zu transformieren. </li><li> Implantat Phosphorionen durch Source / Drain (S / D) Dotieren bei niedriger Energie (5E 15 cm -2) 25. </li><li> Führen Sie Standard - Lithographie durch die I-Line - Stepper mit der Poly-Si - Schicht zu entfernen und das Polysilizium Nanodraht- (pSNW) 25 bilden. Hinweis: Wiederholen Sie Schritt 1.1.3 dop einzupflanzenAmeisen an anderen Orten als S / D-Gebiete mit Poly-Si-Entfernung und der Seitenwand Si Kanäle in einer selbstausrichtenden Art und Weise bilden. </li><li> Führen Sie die Passivierung (200 nm dicke TEOS - Oxidschicht) unter Verwendung von LPCVD bei 780 ° C für 5 Stunden 25. </li><li> Führen Sie Standard-Lithographie durch die I-Line-Stepper mit den Nanodraht-Kanäle und Formtest-Pads zu belichten, indem die zweistufigen Trocken- / Nass Ätzprozess. <ol><li> Wiederholen Sie Schritt 1.1.3. </li><li> Führen Sie die Naßätzprozeß (DHF: HF / H 2 O für 1 min). </li></ol></li></ol></li><li> Wafer Konservierung <ol><li> Verschließen Sie den Wafer in einer Vakuumspeicherbeutel und lagern Sie es in einem elektronischen Trockenschrank (relative Luftfeuchtigkeit &lt;40% bei Raumtemperatur). </li></ol></li></ol> 2. Vorbehandlung des Geräte <ol><li> Gerätereinigung <ol><li> Spülen Sie das Gerät mit reinem Aceton. </li><li> Beschallen (46 kHz, 80 W) ist das Gerät in reinem Aceton für 10 min. </li> &lt;li&gt; Ultraschallbad (46 kHz, 80 W) ist das Gerät in reinem Ethanol (99,5%) für 5 min. </li><li> Föhnen Sie die Oberfläche des Gerätes mit Stickstoff. </li></ol></li><li> Sauerstoffplasma <ol><li> Behandeln Sie das Gerät mit O 2 Plasma bei 18 W für 30 Sekunden. </li></ol></li></ol> 3. Immobilisierung der DNA-Sonde auf der Oberfläche der Vorrichtung <ol><li> Amingruppe Modifikation <ol><li> Eintauchen der Vorrichtung in einer 2,0% (3-Aminopropyl) triethoxysilan (APTES) / Ethanollösung für 30 min. </li><li> Waschen Sie das Gerät mit Ethanol dreimal und dann Sonikat (46 kHz, 80 W) ist das Gerät in Ethanol für 10 min. </li><li> Erhitzen Sie das Gerät auf einer heißen Platte bei 120 ° C für 10 min Amingruppen auf SNWs zu erstellen. </li></ol></li><li> Aldehydgruppe Modifikation <ol><li> Eintauchen der Vorrichtung in 12,5% Glutaraldehyd während 1 Stunde bei Raumtemperatur Aldehydgruppen auf der Oberfläche zu schaffen. Vermeiden Sie Belichtung. </li><li> Waschen Sie das Gerät Witzh 10 mM Natriumphosphatpuffer (Na-PB, pH 7,0) dreimal und dann Föhnen die Oberfläche der Vorrichtung mit Stickstoff. </li></ol></li><li> DNA - Sonde Immobilisierung <ol><li> Tauchen Sie das Gerät in einer Lösung, die 1 &amp; mgr; M DNA-Sonden über Nacht. </li><li> Eintauchen der Vorrichtung in 10 mM Tris - Puffer (pH 8,0) mit 4,0 mM NaBH 3 CN für 30 min die nicht umgesetzten Aldehydgruppen zu blockieren. </li><li> Waschen Sie das Gerät mit Na-PB (pH 7,0) dreimal und dann Föhnen die Oberfläche der Vorrichtung mit Stickstoff. </li></ol></li></ol> 4. Bestätigung und Analyse von Oberflächenmodifizierung auf pSNWFET <ol><li> pH - Profil nach jedem Schritt der Oberflächenmodifikation <ol><li> Bereiten Sie 10 mM Na-PB in pH 3,0 bis 9,0. <ol><li> Herstellung von 10 mM Natriumphosphat , dreibasischem Dodecahydrat (Na 3 PO 4) in deionisiertem Wasser (pH 11,60). </li><li> Herstellung von 10 mM Phosphorsäure (H 3 PO 4) in deionisiertem Wasser(PH 2,35). </li><li> Legen Sie die pH - Elektrode in 500 ml 10 mM Na 3 PO 4 Puffer und mischen diese Lösung mit unterschiedlichen Volumina von 10 mM H 3 PO 4 Puffer , während der pH - Wert Messung zu erhalten Puffer mit pH - Werten von 3,0, 4,0, 5,0, 6,0 , 7.0, 8.0 und 9.0. </li></ol></li><li> AC-Leitfähigkeitsmessung Hinweis: Die Messschaltung einen kleinen Wechselstromsignalgenerator und einen Au Mikrodraht enthalten, der als Flüssigkeit Gate-Elektrode diente. <ol><li> Bestimmen die optimale Flüssigkeits Gate - Spannung (V LG) zur Messung 26 bei jedem Änderungsschritt (Schritte 2.2, 3.1, 3.2 und 3.3). Hinweis: Die elektrischen Eigenschaften der Vorrichtung nach vier Oberflächenmodifikationen an der SNW gemessen wurden, wie in diesem Abschnitt beschrieben. In Schritt 2.2 wird das unmodifizierte pSNWFET die natürliche Oxidschicht enthält, modifiziert; Schritt 3.1 beinhaltet die Vorrichtung mit der Amingruppe von APTES modifizieren; Schritt 3.2 beinhaltet Modifikation mit dem ungeladenenfunktionelle Gruppe von Glutaraldehyd; und Schritt 3.3 beinhaltet DNA-Sonde Modifikation. <ol><li> Geben Sie sich die 10 mM Na-PB (pH 7,0) Lösung der SNW Oberfläche durch eine Spritzenpumpe (Flussrate: 5,0 ml / h) für den direkten Kontakt mit der SNW. </li><li> Messen der Echtzeit - Konduktanz der Vorrichtung während Fegen V LG 0,80-1,30 V. <ol><li> Führen Leitwertmessung durch die Lock-in - Technik 27 bei Raumtemperatur verwendet wird . </li><li> Wandeln die Wechselstromsignale in ein AC-Spannungssignal durch einen rauscharmen Vorverstärker Strom verwendet wird. </li><li> Sammeln Sie Daten auf Leitfähigkeit (G) bei Erhöhung V LG 0,80-1,30 V (Intervall = 0,02 V). </li></ol></li><li> Bestimmen die optimale V LG (empfindlichsten V LG) der Vorrichtung 26. <ol><li> Zeichnen Sie die GV LG Kurven aus Schritt 4.1.2.1.2.3 die Gleichung der Kurve zu erhalten. </li><li> Difzieren die Gleichung, und berechnen Sie die Werte in jedem Punkt von V LG. </li><li> Unterteilen den Wert aus Schritt 4.1.2.1.3.2 von G, und bestimmen die optimale V LG entsprechend der maximalen Anzahl. </li></ol></li></ol></li><li> Messen der Echtzeit-Leitwert des pH-Profil bei jedem Schritt der Oberflächenmodifikation. <ol><li> Führen Leitwertmessung durch die Lock-in - Technik 27 bei Raumtemperatur verwendet wird . </li><li> Konvertieren Sie die AC-Stromsignal in Wechselspannungssignale durch einen rauscharmen Vorverstärker Strom verwendet wird. </li><li> Stellen Sie die optimale V LG für jeden Schritt der Oberflächenmodifikation (Schritt 2.2: V LG = 1,02, Schritt 3.1: V LG = 0,98, Schritt 3.2: V LG = 0,98, und Schritt 3.3: V LG = 1,0). </li><li> Geben Sie sich die 10 mM Na-PB-Lösung mit pH-Werten von 3,0 bis 9,0 auf der SNW Oberfläche (Fließgeschwindigkeit: 5,0 ml / h), Und die Daten auf Konduktanz bei einer Drainspannung von 0,01 V. sammeln </li></ol></li></ol></li></ol></li><li> Messung der elektrischen Eigenschaften (der I D -V BG curve) der Vorrichtung in 10 mM Na-PB (pH 7,0) nach jedem Schritt der Oberflächenmodifikation (Schritte 2.2, 3.1, 3.2 und 3.3.) Hinweis: Die elektrischen Eigenschaften der Vorrichtung nach vier Oberflächenmodifikationen an der SNW wurden gemessen: in Schritt 2.2, der unmodifizierte pSNWFET die native Oxidschicht enthält, modifiziert ist; Schritt 3.1 beinhaltet das Gerät mit der Amingruppe von APTES Modifizierung; Schritt 3.2 bringt Modifikation mit der ungeladenen funktionelle Gruppe von Glutaraldehyd; und Schritt 3.3 bringt DNA-Sonde Modifikation. <ol><li> Liefern die 10 mM Na-PB (pH 7,0) Lösung der SNW Oberfläche (Schritte 2.2, 3.1, 3.2 und 3.3) durch eine Spritzenpumpe (Flussrate: 5,0 ml / h) für den direkten Kontakt mit der SNW. </li><li> Messen Sie die I D </em&gt; Der Vorrichtung (Schritte 2.2, 3.1, 3.2 und 3.3) von einem kommerziellen Halbleiter Analysator und Software. <ol><li> Wählen Sie den &quot;nMOSFET&quot; -Modus. </li><li> Wählen Sie &quot;I D - V BG&quot; Module. Hinweis: I D ist die Drain / Source - Strom und V BG ist die Back - Gate - Spannung. </li><li> Stellen Sie eine konstante Vorspannung (V D = 0,5 V) , während fegt das Gate - Potential (V BG) von -1 bis 3,0 V (Intervall = 0,2 V). </li><li> Klicken Sie auf das Symbol Run I D zu erhalten - V BG Kurven. </li></ol></li></ol></li></ol> 5. DNA Biosensorik Anmerkung: In einem typischen Experiment wurde die I D - V B G Kurve wird dreimal bestimmt , um sicherzustellen , dass keine weitere Variation ist Observed. <ol><li> Bestimmung der Baseline <ol><li> Geben Sie sich die 10 mM Na-PB (pH 7,0) auf die DNA-Sonde immobilisiert SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h), und dann die SNW für 30 min inkubiert. </li><li> Messen Sie die I D des Gerätes (Wiederholen Sie Schritt 4.2.2). </li></ol></li><li> Erfassen von DNA / DNA - Hybridisierung <ol><li> Last 10 pM komplementärer Ziel-DNA an die DNA-Sonde immobilisiert SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h), und dann die SNW für 30 min inkubieren. </li><li> Geben Sie sich die 10 mM Na-PB (pH 7,0) auf die SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h), um die nicht gebundenen Ziel-DNA entfernt zu waschen. </li><li> Wiederholen Sie Schritt 4.2.2 die I D der Vorrichtung zu messen. </li></ol></li><li> Überprüfen Sie noch einmal das Signal von DNA / DNA - Hybridisierung. <ol><li> Last 1 nM Erholung DNA auf ter DNA-Sonde immobilisiert SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h), und dann die SNW für 30 min inkubiert. </li><li> Geben Sie sich die 10 mM Na-PB (pH 7,0) auf die SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h). </li><li> Wiederholen Sie Schritt 4.2.2 die I D der Vorrichtung zu messen. </li></ol></li><li> Negative Kontrolle <ol><li> Last 100 pM nicht komplementäre DNA an die DNA-Sonde immobilisiert SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h), und dann die SNW für 30 min inkubieren. </li><li> Geben Sie sich die 10 mM Na-PB (pH 7,0) auf die SNW Oberfläche für 10 min durch eine Spritzenpumpe (Flussrate: 5,0 ml / h). </li><li> Wiederholen Sie Schritt 4.2.2 die I D der Vorrichtung zu messen. </li></ol></li></ol>

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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Force+titrations+and+ionization+state+sensitive+imaging+of+functional+groups+in+aqueous+solutions+by+chemical+force+microscopy.">Force titrations and ionization state sensitive imaging of functional groups in aqueous solutions by chemical force microscopy.</a> J Am Chem Soc. 119, 2006-2015 (1997).</li><li>Townsend, M. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+evaluation+of+the+FluChip+diagnostic+microarray+for+influenza+virus+surveillance.">Experimental evaluation of the FluChip diagnostic microarray for influenza virus surveillance.</a> J Clin Microbiol. 44, 2863-2871 (2006).</li><li>Wang, L. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+detection+and+differentiation+of+Newcastle+disease+and+avian+influenza+viruses+using+oligonucleotide+microarrays.">Simultaneous detection and differentiation of Newcastle disease and avian influenza viruses using oligonucleotide microarrays.</a> Vet Microbiol. 127, 217-226 (2008).</li><li>Lin, C. -. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+Based+Nanowire+Field-Effect+Transistor+Detection+of+Pathogenic+Avian+Influenza+DNA.">Recovery Based Nanowire Field-Effect Transistor Detection of Pathogenic Avian Influenza DNA.</a> Jpn J Appl Phys. 51 (02BL02), (2012).</li><li>Lee, K. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Well+controlled+assembly+of+silicon+nanowires+by+nanowire+transfer+method.">Well controlled assembly of silicon nanowires by nanowire transfer method.</a> Nanotechnology. 18 (445302), (2007).</li><li>Li, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequence-specific+label-free+DNA+sensors+based+on+silicon+nanowires.">Sequence-specific label-free DNA sensors based on silicon nanowires.</a> Nano Lett. 4, 245-247 (2004).</li><li>McAlpine, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-performance+nanowire+electronics+and+photonics+on+glass+and+plastic+substrates.">High-performance nanowire electronics and photonics on glass and plastic substrates.</a> Nano Lett. 3, 1531-1535 (2003).</li><li>Cui, Y., Wei, Q., Park, H., Lieber, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanowire+nanosensors+for+highly+sensitive+and+selective+detection+of+biological+and+chemical+species.">Nanowire nanosensors for highly sensitive and selective detection of biological and chemical species.</a> Science. 293, 1289-1292 (2001).</li><li>Patolsky, F., Zheng, G., Lieber, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanowire-based+biosensors.">Nanowire-based biosensors.</a> Anal Chem. 78, 4260-4269 (2006).</li><li>Hsiao, C. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+poly-silicon+nanowire+field+effect+transistor+for+biosensing+application.">Novel poly-silicon nanowire field effect transistor for biosensing application.</a> Biosens Bioelectron. 24, 1223-1229 (2009).</li></ol>

The authors have nothing to disclose.

Die Kommerzialisierung der Top-down und Bottom-up - Herstellungsansätze für sSNWFETs schwierig wegen der Kosten betrachtet 32,33, SNW Positionssteuerung 34,35 und seiner niedrigen Produktionsmaßstab 36. Im Gegensatz dazu ist pSNWFETs Herstellung einfach und kostengünstig 37. Durch den Top-Down - Ansatz und die Verbindung mit dem Seitenwandabstandshalter Bildungstechnik (Figur 1) kann die Größe des SNW durch Einstellen der Dauer des reaktiven Plasmaätzen...

Silizium-Nanodraht-Feldeffekttransistoren (SNWFETs) haben die Vorteile der extrem hohe Empfindlichkeit und eine direkte elektrische Reaktionen auf Umweltladungsänderung. In n-Typ SNWFETs Wenn beispielsweise ein negativ (oder positiv) geladenen Molekül die Silizium-Nanodraht (SNW) nähert, werden die Träger in der SNW abgereichertes (oder akkumulieren). Folglich nimmt die Leitfähigkeit des SNWFET (oder erhöht) 1. Daher kann jedes geladene Molekül in der Nähe der Oberfläche der SNW SNWFET Vorrichtung detektiert werden. Vital Biomolekülen einschließlich Enzymen, Proteinen, Nukleotiden und viele Moleküle auf der Zelloberfläche sind Ladungsträger und kann mit SNWFETs überwacht werden. Mit geeigneten Modifikationen, insbesondere eine biomolekulare Sonde auf der SNW Immobilisierung kann ein SNWFET in einen markierungsfreien Biosensor entwickelt werden. Überwachungs Biomarkern verwendet ist kritisch für die Diagnose von Krankheiten. Wie in Tabelle 1 gezeigt, haben mehrere Studien verwendet NWFET-basierten Biosensoren für die markierungsfreie, ultra-hoher Empfindlichkeit und Echtzeit - Erkennung von verschiedenen biologischen Ziele, einschließlich eines einzelnen Virus 2, Adenosintriphosphat und Kinase - 3 - Bindung, neuronale Signale 4, Metallionen 5,6, bakterielle Toxine 7, Dopamin 8, DNA 9-11, RNA 12,13, Enzym und Krebs - Biomarker 14-19, menschliche Hormone 20 und Zytokine 21,22. Diese Studien haben gezeigt, dass NWFET-basierten Biosensoren eine leistungsfähige Detektionsplattform für ein breites Spektrum an biologischen und chemischen Spezies in einer Lösung darstellen. In SNWFET-Biosensoren, die Sonde auf der SNW immobilisierte Oberfläche der Vorrichtung erkennt eine spezifische BioTarget. ein bioPROBE immobilisieren beinhaltet in der Regel eine Reihe von Schritten, und es ist wichtig, dass jeder Schritt richtig, das ordnungsgemäße Funktionieren des Biosensors, um sicherzustellen, durchgeführt wird. Verschiedene Techniken wurden zur Analyse der s entwickelturface Zusammensetzung, einschließlich der Röntgenphotoelektronenspektroskopie (XPS), Ellipsometrie, Kontaktwinkelmessung, Rasterkraftmikroskopie (AFM) und Rasterelektronenmikroskopie (SEM). Methoden wie AFM und SEM bieten einen direkten Beweis für bioPROBE Immobilisierung auf der Nanodraht-Gerät, während Methoden wie XPS, Ellipsometrie und Kontaktwinkelmessung auf parallelen Versuchen an anderen ähnlichen Materialien durchgeführt abhängig sind. In diesem Bericht beschreiben wir die Bestätigung jeder Änderung Schritt durch zwei unabhängige Methoden. XPS wird verwendet, um die Konzentrationen an spezifischen Atome auf Polysilicium-Wafern und Variationen in den elektrischen Eigenschaften der Vorrichtung gemessen werden, direkt auf die Ladungsänderung an der Oberfläche zu bestätigen SNW zu untersuchen. Wir beschäftigen DNA Biosensor von polykristallinem SNWFETs mit (pSNWFETs) als ein Beispiel dieses Protokoll zu illustrieren. eine DNA-Sonde auf der SNW Oberfläche immobilisieren umfasst drei Schritte: Amingruppe Modifikation auf der nativen Hydroxyl-Oberfläche des SNW, aldehyd Gruppe Modifikation und 5&#39;-aminomodifizierten DNA-Sonde Immobilisierung. An jedem Änderungsschritt kann die Vorrichtung direkt auf die Veränderung in der Ladung der funktionellen Gruppe an der Oberfläche immobilisiert SNW erfassen, weil die Oberflächenladungen lokale Grenzflächenpotentialänderungen über dem Gate - Dielektrikum führen, die den Kanalstrom und Konduktanz 1 verändern. Kosten der SNW Oberfläche umgibt, kann elektrisch die elektrischen Eigenschaften der pSNWFET Gerät modulieren; Daher spielen die Oberflächeneigenschaften der SNW eine entscheidende Rolle bei der elektrischen Eigenschaften von pSNWFET Geräte zu bestimmen. In den berichteten Verfahren kann die Immobilisierung eines bioPROBE auf der SNW Oberfläche direkt durch elektrische Messung bestimmt und bestätigt werden, und das Gerät ist für die Biosensorik Anwendungen vorbereitet.

<table border="0" cellpadding="0" cellspacing="0" width="862">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Acetone</td>
			<td style="width:191px;">ECHO</td>
			<td style="width:179px;">AH-3102</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:327px;">(3-Amonopropyl)triethoxysilane (APTES), &#8805;98%</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:179px;">A3648</td>
			<td>Danger</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Ethanol, anhydrous, 99.5%</td>
			<td style="width:191px;">ECHO</td>
			<td style="width:179px;">484000203108A-72EC</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Glutaraldehyde solution (GA), 50%</td>
			<td style="width:191px;">Sigma-Aldrich</td>
			<td style="width:179px;">G7651</td>
			<td>Avoid light</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Sodium cyanoborohydride, &#8805;95.0%&#160;</td>
			<td style="width:191px;">Fluka</td>
			<td style="width:179px;">71435</td>
			<td>Danger and deliquescent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:327px;">Sodium phosphate tribasic dodecahydrate, &#8805;98%</td>
			<td style="width:191px;">Sigma</td>
			<td style="width:179px;">04277</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Phosphoric acid, &#8805;99.0%</td>
			<td style="width:191px;">Fluka</td>
			<td style="width:179px;">79622</td>
			<td>Deliquescent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Photoresist (iP3650)</td>
			<td style="width:191px;">Tokyo Ohka Kogyo Co., LTD</td>
			<td style="width:179px;">THMR-iP3650 HP</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Synthetic oligonucleotides, HPLC purified</td>
			<td style="width:191px;">Protech Technology</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:327px;">Tris(hydroxymethyl)aminomethane (Tris), &#8805;99.8%</td>
			<td style="width:191px;">USB</td>
			<td style="width:179px;">75825</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Keithley 2636 System SourceMeter</td>
			<td style="width:191px;">Keithley</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:327px;">SR830 DSP Lock-In Amplifier</td>
			<td style="width:191px;">Stanford Research Systems</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:327px;">SR570 Low-noise Current Preamplifier</td>
			<td style="width:191px;">Stanford Research Systems</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:327px;">Ni PXI Express</td>
			<td style="width:191px;">National Instruments</td>
			<td style="width:179px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation of silicon nanowire field-effect transistor for chemical and biosensing applications

Surveillance using biomarkers is critical for the early detection, rapid intervention, and reduction in the incidence of diseases. In this study, we describe the preparation of polycrystalline silicon nanowire field-effect transistors (pSNWFETs) that serve as biosensing devices for biomarker detection. A protocol for chemical and biomolecular sensing by using pSNWFETs is presented. The pSNWFET device was demonstrated to be a promising transducer for real-time, label-free, and ultra-high-sensitivity biosensing applications. The source/drain channel conductivity of a pSNWFET is sensitive to changes in the environment around its silicon nanowire (SNW) surface. Thus, by immobilizing probes on the SNW surface, the pSNWFET can be used to detect various biotargets ranging from small molecules (dopamine) to macromolecules (DNA and proteins). Immobilizing a bioprobe on the SNW surface, which is a multistep procedure, is vital for determining the specificity of the biosensor. It is essential that every step of the immobilization procedure is correctly performed. We verified surface modifications by directly observing the shift in the electric properties of the pSNWFET following each modification step. Additionally, X-ray photoelectron spectroscopy was used to examine the surface composition following each modification. Finally, we demonstrated DNA sensing on the pSNWFET. This protocol provides step-by-step procedures for verifying bioprobe immobilization and subsequent DNA biosensing application.

Verschiedene SNWFETs wurden als Wandler von Biosensoren (Tabelle 1) dienen berichtet. Einkristalline SNWFETs (sSNWFETs) und pSNWFETs zeigen vergleichbare elektrische Eigenschaften als Wandler in wässrigen Lösungen, und beide haben viele Biosensor-Anwendungen berichtet. Ein vorteilhaftes Merkmal der pSNWFET Gerät in dieser Studie verwendet wird , ist seine einfache und kostengünstige Herstellungsverfahren. 1a zeigt die wichtigsten Schritte , die in de...

Watch this Scientific Journal Video about Preparation of Silicon Nanowire Field-effect Transistor for Chemical and Biosensing Applications at JoVE.com

Preparation of Silicon Nanowire Field-effect Transistor for Chemical and Biosensing Applications

We describe key steps for biosensing by using polysilicon nanowire field-effect transistors, including the preparation of the device and the immobilization and confirmation of a DNA molecular probe on the nanowire surface, as well as conditions for DNA sensing.

Herstellung von Silizium-Nanodraht-Feldeffekttransistor für chemische und Biosensorik Anwendungen

Surveillance using biomarkers is critical for the early detection, rapid intervention, and reduction in the incidence of diseases. In this study, we ...

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11.0K Aufrufe.  National Chiao Tung University. We describe key steps for biosensing by using polysilicon nanowire field-effect transistors, including the preparation of the device and the immobilization and confirmation of a DNA molecular probe on the nanowire surface, as well as conditions for DNA sensing.

Serie: Preparation of Silicon Nanowire Field-effect Transistor for Chemical and Biosensing Applications

Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium

The development of hybrid electronic devices relies in large part on the integration of (bio)organic materials and inorganic semiconductors through a stable interface that permits efficient electron transport and protects underlying substrates from oxidative degradation. Group IV semiconductors can be effectively protected with highly-ordered self-assembled monolayers (SAMs) composed of simple alkyl chains that act as impervious barriers to both organic and aqueous solutions. Simple alkyl SAMs, however, are inert and not amenable to traditional patterning techniques. The motivation for immobilizing organic molecular systems on semiconductors is to impart new functionality to the surface that can provide optical, electronic, and mechanical function, as well as chemical and biological activity. 
Microcontact printing (&mu;CP) is a soft-lithographic technique for patterning SAMs on myriad surfaces.1-9 Despite its simplicity and versatility, the approach has been largely limited to noble metal surfaces and has not been well developed for pattern transfer to technologically important substrates such as oxide-free silicon and germanium. Furthermore, because this technique relies on the ink diffusion to transfer pattern from the elastomer to substrate, the resolution of such traditional printing is essentially limited to near 1 &mu;m.10-16
In contrast to traditional printing, inkless &mu;CP patterning relies on a specific reaction between a surface-immobilized substrate and a stamp-bound catalyst. Because the technique does not rely on diffusive SAM formation, it significantly expands the diversity of patternable surfaces. In addition, the inkless technique obviates the feature size limitations imposed by molecular diffusion, facilitating replication of very small (&lt;200 nm) features.17-23 However, up till now, inkless &mu;CP has been mainly used for patterning relatively disordered molecular systems, which do not protect underlying surfaces from degradation.
Here, we report a simple, reliable high-throughput method for patterning passivated silicon and germanium with reactive organic monolayers and demonstrate selective functionalization of the patterned substrates with both small molecules and proteins. The technique utilizes a preformed NHS-reactive bilayered system on oxide-free silicon and germanium. The NHS moiety is hydrolyzed in a pattern-specific manner with a sulfonic acid-modified acrylate stamp to produce chemically distinct patterns of NHS-activated and free carboxylic acids. A significant limitation to the resolution of many &mu;CP techniques is the use of PDMS material which lacks the mechanical rigidity necessary for high fidelity transfer. To alleviate this limitation we utilized a polyurethane acrylate polymer, a relatively rigid material that can be easily functionalized with different organic moieties. Our patterning approach completely protects both silicon and germanium from chemical oxidation, provides precise control over the shape and size of the patterned features, and gives ready access to chemically discriminated patterns that can be further functionalized with both organic and biological molecules. The approach is general and applicable to other technologically-relevant surfaces.

Here we describe a simple method for patterning oxide-free silicon and germanium with reactive organic monolayers and demonstrate functionalization of the patterned substrates with small molecules and proteins. The approach completely protects surfaces from chemical oxidation, provides precise control over feature morphology, and provides ready access to chemically discriminated patterns.

Soft-Lithographie Funktionalisierung und Strukturierung Oxydfreie Silizium und Germanium

The development of hybrid electronic devices relies in large part on the integration of (bio)organic materials and inorganic semiconductors through a ...

Forschung

Biotechnik

Preparation of 3D Fibrin Scaffolds for Stem Cell Culture Applications

Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues 2. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue.3 A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo 4. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors 5. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside 6,7.
 This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis step for the fibrinogen solution to remove citrates that inhibit polymerization. These detailed methods rely on fibrinogen concentrations determined to be optimal for embryonic and induced pluripotent stem cell culture. Other groups have further investigated fibrin scaffolds for a wide range of cell types and applications - demonstrating the versatility of this approach 8-12.

This work details the preparation of 3D fibrin scaffolds for culturing and differentiating plutipotent stem cells. Such scaffolds can be used to screen the effects of various biological compounds on stem cell behavior as well as modified to contain drug delivery systems.

Erstellung von 3D-Fibrin-Gerüste für Stem Cell Culture Anwendungen

Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells ...

Porous Silicon Microparticles for Delivery of siRNA Therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the successful implementation of siRNA therapy requires the use of delivery platforms that can overcome the major challenges of siRNA delivery, such as enzymatic degradation, low intracellular uptake and lysosomal entrapment. Here, a protocol for the preparation and use of a biocompatible and effective siRNA delivery system is presented. This platform consists of polyethylenimine (PEI) and arginine (Arg)-grafted porous silicon microparticles, which can be loaded with siRNA by performing a simple mixing step. The silicon particles are gradually degraded over time, thereby triggering the formation of Arg-PEI/siRNA nanoparticles. This delivery vehicle provides a means for protecting and internalizing siRNA, without causing cytotoxicity. The major steps of polycation functionalization, particle characterization, and siRNA loading are outlined in detail. In addition, the procedures for determining particle uptake, cytotoxicity, and transfection efficacy are also described.

Delivery remains the main challenge for the therapeutic implementation of small interfering RNA (siRNA). This protocol involves the use of a multifunctional and biocompatible siRNA delivery platform, consisting of arginine and polyethylenimine grafted porous silicon microparticles.

Poröses Silizium Mikropartikel für die Lieferung von siRNA-Therapeutika

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the ...

The Synthesis of RGD-functionalized Hydrogels as a Tool for Therapeutic Applications

The use of polymers as biomaterials has provided significant advantages in therapeutic applications. In particular, the possibility to modify and functionalize polymer chains with compounds that are able to improve biocompatibility, mechanical properties, or cell viability allows the design of novel materials to meet new challenges in the biomedical field. With the polymer functionalization strategies, click chemistry is a powerful tool to improve cell-compatibility and drug delivery properties of polymeric devices. Similarly, the fundamental need of biomedicine to use sterile tools to avoid potential adverse-side effects, such as toxicity or contamination of the biological environment, gives rise to increasing interest in the microwave-assisted strategy.
The combination of click chemistry and the microwave-assisted method is suitable to produce biocompatible hydrogels with desired functionalities and improved performances in biomedical applications. This work aims to synthesize RGD-functionalized hydrogels. RGD (arginylglycylaspartic acid) is a tripeptide that can mimic cell adhesion proteins and bind to cell-surface receptors, creating a hospitable microenvironment for cells within the 3D polymeric network of the hydrogels. RGD functionalization occurs through Huisgen 1,3-dipolar cycloaddition. Some PAA carboxyl groups are modified with an alkyne moiety, whereas RGD is functionalized with azido acid as the terminal residue of the peptide sequence. Finally, both products are used in a copper catalyzed click reaction to permanently link the peptide to PAA. This modified polymer is used with carbomer, agarose and polyethylene glycol (PEG) to synthesize a hydrogel matrix. The 3D structure is formed due to an esterification reaction involving carboxyl groups from PAA and carbomer and hydroxyl groups from agarose and PEG through microwave-assisted polycondensation. The efficiency of the gelation mechanism ensures a high degree of RGD functionalization. In addition, the procedure to load therapeutic compounds or biological tools within this functionalized network is very simple and reproducible.

We present a protocol for the synthesis of RGD-functionalized hydrogels as devices for cell and drug delivery. The procedure involves copper catalyzed alkyne-azide cycloaddition (CuAAC) between alkyne-modified polyacrylic acid (PAA) and a RGD-azide derivative. The hydrogels are formed using microwave-assisted polycondensation and their physicochemical properties are investigated.

Die Synthese von RGD-funktionalisierten Hydrogele als Werkzeug für therapeutische Anwendungen

The use of polymers as biomaterials has provided significant advantages in therapeutic applications. In particular, the possibility to modify and ...

Light-mediated Formation and Patterning of Hydrogels for Cell Culture Applications

Click chemistries have been investigated for use in numerous biomaterials applications, including drug delivery, tissue engineering, and cell culture. In particular, light-mediated click reactions, such as photoinitiated thiol&#8722;ene and thiol&#8722;yne reactions, afford spatiotemporal control over material properties and allow the design of systems with a high degree of user-directed property control. Fabrication and modification of hydrogel-based biomaterials using the precision afforded by light and the versatility offered by these thiol&#8722;X photoclick chemistries are of growing interest, particularly for the culture of cells within well-defined, biomimetic microenvironments. Here, we describe methods for the photoencapsulation of cells and subsequent photopatterning of biochemical cues within hydrogel matrices using versatile and modular building blocks polymerized by a thiol&#8722;ene photoclick reaction. Specifically, an approach is presented for constructing hydrogels from allyloxycarbonyl (Alloc)-functionalized peptide crosslinks and pendant peptide moieties and thiol-functionalized poly(ethylene glycol) (PEG) that rapidly polymerize in the presence of lithium acylphosphinate photoinitiator and cytocompatible doses of long wavelength ultraviolet (UV) light. Facile techniques to visualize photopatterning and quantify the concentration of peptides added are described. Additionally, methods are established for encapsulating cells, specifically human mesenchymal stem cells, and determining their viability and activity. While the formation and initial patterning of thiol-alloc hydrogels are shown here, these techniques broadly may be applied to a number of other light and radical-initiated material systems (e.g., thiol-norbornene, thiol-acrylate) to generate patterned substrates.

We describe a sequential process for light-mediated formation and subsequent biochemical patterning of synthetic hydrogel matrices for three-dimensional cell culture applications. The construction and modification of hydrogels with cytocompatible photoclick chemistry is demonstrated. Additionally, facile techniques to quantify and observe patterns and determine cell viability within these hydrogels are presented.

Licht-vermittelte Bildung und Musterung von Hydrogelen für Zellkulturanwendungen

Click chemistries have been investigated for use in numerous biomaterials applications, including drug delivery, tissue engineering, and cell culture. In ...

Extraction of Plant-based Capsules for Microencapsulation Applications

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin exine capsules (SECs) are obtained when spores or pollen are processed so as to remove the internal sporoplasmic contents. The resulting hollow microcapsules exhibit a high degree of micromeritic uniformity and retain intricate microstructural features related to the particular plant species. Herein, we demonstrate a streamlined process for the production of SECs from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs. The current SEC isolation procedure has been recently optimized to significantly reduce the processing requirements which are conventionally used in SEC isolation, and to ensure the production of intact microcapsules. Natural L. clavatum spores are defatted with acetone, treated with phosphoric acid, and extensively washed to remove sporoplasmic contents. After acetone defatting, a single processing step using 85% phosphoric acid has been shown to remove all sporoplasmic contents. By limiting the acid processing time to 30 hr, it is possible to isolate clean SECs and avoid SEC fracturing, which has been shown to occur with prolonged processing time. Extensive washing with water, dilute acids, dilute bases, and solvents ensures that all sporoplasmic material and chemical residues are adequately removed. The vacuum loading technique is utilized to load a model protein (Bovine Serum Albumin) as a representative hydrophilic compound. Vacuum loading provides a simple technique to load various compounds without the need for harsh solvents or undesirable chemicals which are often required in other microencapsulation protocols. Based on these isolation and loading protocols, SECs provide a promising material for use in a diverse range of microencapsulation applications, such as, therapeutics, foods, cosmetics, and personal care products.

This protocol/manuscript describes a streamlined process for the production of sporopollenin exine capsules (SECs) from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs.

Extraktion von Pflanzenbasis Kapseln für Mikroverkapselung Anwendungen

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin ...

Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest regarding the use of bioinspired nanoscale hydroxyapatite (nHA). However, biological apatite is known to be calcium-deficient and carbonate-substituted with a nanoscale platelet-like morphology. Bioinspired nHA has the potential to stimulate optimal bone tissue regeneration due to its similarity to bone and tooth enamel mineral. Many of the methods currently used to fabricate nHA both in the laboratory and commercially, involve lengthy processes and complex equipment. Therefore, the aim of this study was to develop a rapid and reliable method to prepare high quality bioinspired nHA. The rapid mixing method developed was based upon an acid-base reaction involving calcium hydroxide and phosphoric acid. Briefly, a phosphoric acid solution was poured into a calcium hydroxide solution followed by stirring, washing and drying stages. Part of the batch was sintered at 1,000 &#176;C for 2 h in order to investigate the products&#39; high temperature stability. X-ray diffraction analysis showed the successful formation of HA, which showed thermal decomposition to &#946;-tricalcium phosphate after high temperature processing, which is typical for calcium-deficient HA. Fourier transform infrared spectroscopy showed the presence of carbonate groups in the precipitated product. The nHA particles had a low aspect ratio with approximate dimensions of 50 x 30 nm, close to the dimensions of biological apatite. The material was also calcium deficient with a Ca:P molar ratio of 1.63, which like biological apatite is lower than the stoichiometric HA ratio of 1.67. This new method is therefore a reliable and far more convenient process for the manufacture of bioinspired nHA, overcoming the need for lengthy titrations and complex equipment. The resulting bioinspired HA product is suitable for use in a wide variety of medical and consumer health applications.

This paper describes a novel method for the rapid manufacture of high quality bioinspired nanoscale hydroxyapatite. This biomaterial is of great significance in the manufacture of a wide range of innovative medical devices for clinical applications in orthopedics, craniofacial surgery and dentistry.

Rapid-Mix Herstellung von Bioinspirierte Nanoskalige Hydroxyapatit für biomedizinische Anwendungen

Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest ...

Rapid Fabrication of Custom Microfluidic Devices for Research and Educational Applications

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to submillimeter scales. A rapid increase in the use of this technology in the biological sciences has prompted a need for methods that are accessible to a wide range of research groups. Current fabrication standards, such as PDMS bonding, require expensive and time consuming lithographic and bonding techniques. A viable alternative is the use of equipment and materials that are easily affordable, require minimal expertise and allow for the rapid iteration of designs. In this work we describe a protocol for designing and producing PET-laminates (PETLs), microfluidic devices that are inexpensive, easy to fabricate, and consume significantly less time to generate than other approaches to microfluidics technology. They consist of thermally bonded film sheets, in which channels and other features are defined using a craft cutter. PETLs solve field-specific technical challenges while dramatically reducing obstacles to adoption. This approach facilitates the accessibility of microfluidics devices in both research and educational settings, providing a reliable platform for new methods of inquiry.

Here we present a protocol to design and fabricate custom microfluidic devices with minimal financial and time investment. The aim is to facilitate the adoption of microfluidic technologies in biomedical research laboratories and educational settings.

Schnelle Herstellung von kundenspezifischen mikrofluidischen Geräten für Forschungs- und Bildungsanwendungen

Microfluidic devices allow for the manipulation of fluids, particles, cells, micro-sized organs or organisms in channels ranging from the nano to ...

Synthesis of Near-Infrared Emitting Gold Nanoclusters for Biological Applications

Over the past decade, fluorescent gold nanoclusters (AuNCs) have witnessed growing popularity in biological applications and enormous efforts have been devoted to their development. In this protocol, a recently developed, facile method for preparation of water soluble, biocompatible, and colloidally stable near-infrared emitting AuNCs have been described in detail. This room-temperature, bottom-up chemical synthesis provides easily functionalizable AuNCs capped with thioctic acid and thiol-modified polyethylene glycol in aqueous solution. The synthetic approach requires neither organic solvents or additional ligand exchange nor extensive knowledge of synthetic chemistry to reproduce. The resulting AuNCs offer free surface carboxylic acids, which can be functionalized with various biological molecules bearing a free amine group without adversely affecting the photoluminescent properties of the AuNCs. A quick, reliable procedure for flow cytometric quantification and confocal microscopic imaging of AuNC uptake by HeLa cells also been described. Due to the large Stokes shift, proper setting of filters in flow cytometry and confocal microscopy is necessary for efficient detection of near-infrared photoluminescence of AuNCs.

A reliable and easily reproducible method for preparation of functionalizable, near-infrared emitting photoluminescent gold nanoclusters and their direct detection inside HeLa cells by flow cytometry and confocal laser scanning microscopy is described.

Synthese von Nahinfrarot emittierenden Gold-Nanoclustern für biologische Anwendungen

Over the past decade, fluorescent gold nanoclusters (AuNCs) have witnessed growing popularity in biological applications and enormous efforts have been ...

Injectable Supramolecular Polymer-Nanoparticle Hydrogels for Cell and Drug Delivery Applications

These methods describe how to formulate injectable, supramolecular polymer-nanoparticle (PNP) hydrogels for&#160;use as biomaterials. PNP hydrogels are composed of two components: hydrophobically modified cellulose as the network polymer and self-assembled core-shell nanoparticles that act as non-covalent cross linkers through dynamic, multivalent interactions. These methods describe both the formation of these self-assembled nanoparticles through nanoprecipitation as well as the formulation and mixing of the two components to form hydrogels with tunable mechanical properties. The use of dynamic light scattering (DLS) and rheology to characterize the quality of the synthesized materials is also detailed. Finally, the utility of these hydrogels for drug delivery, biopharmaceutical stabilization, and cell encapsulation and delivery is demonstrated through in vitro experiments to characterize&#160;drug release, thermal stability, and cell settling and viability. Due to its biocompatibility, injectability, and mild gel formation conditions, this hydrogel system is a readily tunable platform suitable for a range of biomedical applications.

This protocol describes the synthesis and formulation of injectable, supramolecular polymer-nanoparticle (PNP) hydrogel biomaterials. Applications of these materials for drug delivery, biopharmaceutical stabilization, and cell encapsulation and delivery are demonstrated.

Injizierbare supramolekulare Polymer-Nanopartikel-Hydrogele für Zell- und Arzneimittelverabreichungsanwendungen

These methods describe how to formulate injectable, supramolecular polymer-nanoparticle (PNP) hydrogels for&#160;use as biomaterials. PNP hydrogels are ...