Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite

Thermocapillary convection is an important research subject in microgravity fluid physics. The experimental study on surface waves of thermocapillary ...

Chinese Academy of Sciences

University of Chinese Academy of Sciences

Manganese-doped ZnS quantum dots (ZnS:Mn(II) QDs) were synthesized and modified with L-cysteine (L-Cys) and 6-mercaptonicotinic acid (MNA). This prevents the aggregation of the QDs and makes them available for the interaction with Cu(II) ions via Cu(II)-S interaction. As a result, the fluorescence of the QDs is quenched by Cu(II) due to an electron transfer mechanism. The QDs display two emission peaks under 325 nm excitation, one (being red) peaking at 593 nm, the other (blue) at 412 nm. The red fluorescence is strongly quenched, while the blue fluorescence is not affected. An easily distinguishable color change from orange red to purple can be observed in fluorescence as the concentration of Cu(II) is increased. The probe is selective over commonly encountered other ions. The ratio of fluorescence intensities at 593 and 412 nm increases linearly in the 5 to 500 nM Cu(II) concentration range, and the detection limit is 1.2 nM. Graphical abstract Schematic of the preparation of manganese-doped quantum dots functionalized with L-cysteine and 6-mercaptonicotinic acid for selective and sensitive visual detection of copper ions.

Functional ZnS:Mn(II) quantum dot modified with L-cysteine and 6-mercaptonicotinic acid as a fluorometric probe for copper(II).

&#x4E00;&#x79CD;&#x65B9;&#x6CD5;&#x6C5E;&#x79BB;&#x5B50; (Hg(2+)) &#x9065;&#x611F;&#x57FA;&#x4E8E; Hg(2+) &#x8BF1;&#x5BFC;&#x805A;&#x5408;&#x7684;&#x5B98;&#x80FD;&#x7684;&#x80F8;&#x817A;&#x5627;&#x5576; (T)-SH-&#x91D1;&#x7EB3;&#x7C73;&#x7C92;&#x5B50; (AuNPs) &#x6709;&#x62A5;&#x5BFC;&#x3002;T SH &#x914D;&#xFF0C;&#x6211;&#x4EEC;&#x5408;&#x6210;&#x5F88;&#x5BB9;&#x6613;&#x53EF;&#x4EE5;&#x518D;&#x901A;&#x8FC7;&#x975E;&#x76DF;-S &#x503A;&#x5238; AuNPs &#x7684;&#x8868;&#x9762;&#x52A0;&#x4E0A;&#xFF0C;&#x5E76;&#x53EF;&#x4EE5;&#x8BC6;&#x522B; Hg(2+) &#x9AD8;&#x9009;&#x62E9;&#x6027;&#x7684;&#x5F62;&#x6210;&#x4E0E;&#x4EB2;&#x548C;&#x529B;&#x5F3A;&#x7684; T Hg T &#x590D;&#x6742;&#x3002;T-SH-&#x5B98;&#x80FD; AuNPs (T-S-AuNPs&#xFF09; &#x4F20;&#x611F;&#x5668;&#xFF0C;Hg(2+)&#xFF0C;&#x52A0;&#x5165; T Hg T &#x590D;&#x6742;&#x7684;&#x5F62;&#x6210;&#x8BF1;&#x5BFC;&#x805A;&#x5408;&#x7684; T-S-AuNPs &#x548C;&#x7ED3;&#x679C;&#x7684;&#x989C;&#x8272;&#x548C;&#x7D2B;&#x5916;&#x53EF;&#x89C1;&#x5438;&#x6536;&#x5149;&#x8C31;&#x53D1;&#x751F;&#x91CD;&#x5927;&#x7684;&#x6539;&#x53D8;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x6211;&#x4EEC;&#x7684;&#x65B9;&#x6CD5;&#x53EF;&#x7528;&#x4E8E;&#x5728;&#x6C34;&#x6EB6;&#x6DB2;&#x4E2D;&#x7684; Hg(2+) &#x5FEB;&#x901F;&#x3001; &#x65B9;&#x4FBF;&#x3001; &#x53EF;&#x9760;&#x7B5B;&#x9009;&#x7684;&#x9AD8;&#x7075;&#x654F;&#x5EA6; (2.8 nM&#xFF09; &#x548C;&#x5BF9;&#x7ADE;&#x4E89;&#x5BF9;&#x624B;&#x7684;&#x5206;&#x6790;&#x7269;&#x7684;&#x9009;&#x62E9;&#x6027;&#x3002;&#x53D1;&#x8FBE;&#x7684;&#x65B9;&#x6CD5;&#x6210;&#x529F;&#x5E94;&#x7528;&#x4E8E;&#x5B9E;&#x9645;&#x73AF;&#x5883;&#x6837;&#x54C1;&#x4E2D;&#x9065;&#x611F;&#x7684; Hg(2+)&#x3002;

N-1-(2-&#x4E09;) &#x80F8;&#x817A;&#x5627;&#x5576;&#x4FEE;&#x9970;&#x7684;&#x91D1;&#x7EB3;&#x7C73;&#x7C92;&#x5B50;&#xFF1A; &#x4E3A; Hg2 + &#x5316;&#x5B66;&#x9AD8;&#x5EA6;&#x9009;&#x62E9;&#x6027;&#x7684;&#x548C;&#x654F;&#x611F;&#x7684;&#x6BD4;&#x8272;&#x654F;&#x611F;&#x5668;&#x3002;

An approach for mercury ions (Hg(2+)) sensing based on the Hg(2+)-induced aggregation of thymine (T)-SH-functionalized gold nanoparticles (AuNPs) has been reported. The T-SH ligands that we synthesized can easily be coupled to the surface of AuNPs through the Au-S bond and can recognize Hg(2+) with high selectivity by forming a T-Hg-T complex with strong affinity. For the T-SH-functionalized AuNPs (T-S-AuNPs) sensor, upon addition of Hg(2+), the formation of the T-Hg-T complex induces aggregation of T-S-AuNPs and results in a significant change of color and UV-Vis absorption spectra. Thus, our method can be used for the rapid, easy and reliable screening of Hg(2+) in aqueous solution, with high sensitivity (2.8 nM) and selectivity over competing analytes. The developed method is successfully applied to the sensing of Hg(2+) in real environmental samples.

N-1-(2-mercaptoethyl)thymine modification of gold nanoparticles: a highly selective and sensitive colorimetric chemosensor for Hg2+.

Une approche pour les ions de mercure (Hg(2+)) de d&eacute;tection bas&eacute; sur l&#39;agr&eacute;gation induite par le Hg(2+) de nanoparticules d&#39;or (AuNPs) de la thymine (T) - SH - fonctionnalis&eacute; a &eacute;t&eacute; signal&eacute;e. Les ligands T-SH qui nous avons synth&eacute;tis&eacute;s peuvent facilement &ecirc;tre coupl&eacute;s &agrave; la surface du AuNPs par le biais de la liaison S-UA et peuvent reconna&icirc;tre Hg(2+) &agrave; haute s&eacute;lectivit&eacute; en formant un complexe Hg-T-T avec une forte affinit&eacute;. Pour le capteur de AuNPs T-SH fonctionnalis&eacute;s (T-S-AuNPs), lors de l&#39;addition de Hg(2+), la formation du complexe Hg-TT induit l&#39;agr&eacute;gation de S-T-AuNPs et conduit &agrave; un changement significatif de la couleur et le spectre d&#39;absorption UV-Vis. Ainsi, notre m&eacute;thode peut &ecirc;tre utilis&eacute;e pour le d&eacute;pistage rapid, facile et fiable de Hg(2+) en solution aqueuse, &agrave; haute sensibilit&eacute; (2,8 nM) et la s&eacute;lectivit&eacute; sur les analytes concurrentes. La m&eacute;thode d&eacute;velopp&eacute;e est appliqu&eacute;e avec succ&egrave;s &agrave; la t&eacute;l&eacute;d&eacute;tection de Hg(2+) dans des &eacute;chantillons environnementaux r&eacute;els.

N - 1-(2-thio&eacute;thyl&egrave;ne) modification de la thymine de nanoparticules d&#39;or : un senseur colorim&eacute;trique hautement s&eacute;lective et sensible pour Hg2 +.

Ein Ansatz f&uuml;r Quecksilber-Ionen (Hg(2+)) Erkennung anhand der Hg(2+)-induzierte Aggregation von Thymin (T) - SH - funktionalisierten gold-Nanopartikeln (AuNPs) wurde berichtet. Die T-SH Liganden, die wir synthetisiert koppelbar leicht an die Oberfl&auml;che des AuNPs durch das Au-S-Band und k&ouml;nnen Hg(2+) mit hoher Selektivit&auml;t durch die Bildung eines T-Hg-T-Komplexes mit starken Affinit&auml;t erkennen. F&uuml;r den T-SH-funktionalisierten AuNPs (T-S-AuNPs)-Sensor nach Zusatz von Hg(2+) induziert die Bildung von der T-Hg-T-Komplex Aggregation von T-S-AuNPs und f&uuml;hrt zu eine bedeutende &Auml;nderung von Farbe und UV-Vis-Absorptionsspektren. So kann unsere Methode f&uuml;r das schnelle, einfache und zuverl&auml;ssige Screening von Hg(2+) in w&auml;ssriger L&ouml;sung verwendet werden, mit hoher Empfindlichkeit (2,8 nM) und Selektivit&auml;t &uuml;ber konkurrierende Analyten. Die entwickelte Methode wird erfolgreich eingesetzt, um die Erkennung von Hg(2+) in richtiger Umweltproben.

N - 1-(2-Mercaptoethyl) Thymin Modifikation von gold-Nanopartikeln: eine sehr selektive und sensible farbmetrisch Chemorezeptor f&uuml;r Hg2 +.

Un approccio per gli ioni di mercurio (Hg(2+)) di rilevamento basato sull&#39;aggregazione indotta da Hg(2+) di timina (T) - SH - funzionalizzato nanoparticelle d&#39;oro (AuNPs) &egrave; stato segnalato. I T-SH ligandi che abbiamo sintetizzati possono essere facilmente accoppiati alla superficie del AuNPs attraverso il legame Au-S e in grado di riconoscere Hg(2+) con alta selettivit&agrave; formando un complesso T-Hg-T con forte affinit&agrave;. Per il sensore di T-SH-funzionalizzati AuNPs (AuNPs-S-T), con l&#39;aggiunta di Hg(2+), la formazione del complesso T-Hg-T induce aggregazione del AuNPs-T-S e si traduce in un significativo cambiamento di colore e spettri di assorbimento UV-Vis. Cos&igrave;, il nostro metodo pu&ograve; essere utilizzato per lo screening rapido, facile e affidabile di Hg(2+) in soluzione acquosa, ad alta sensibilit&agrave; (2,8 nM) e la selettivit&agrave; su analiti concorrenti. Il metodo sviluppato &egrave; applicato con successo per il rilevamento di Hg(2+) in campioni ambientali reali.

N - 1-(2-mercaptoethyl) modifica di timina di nanoparticelle d&#39;oro: un chemosensor altamente selettivo e sensibile colorimetrico per Hg2 +.

&#x30A2;&#x30D7;&#x30ED;&#x30FC;&#x30C1;&#x306E;&#x6C34;&#x9280;&#x30A4;&#x30AA;&#x30F3; (Hg(2+)) &#x30D9;&#x30FC;&#x30B9; &#x30C1;&#x30DF;&#x30F3; (T) - SH - &#x4FEE;&#x98FE;&#x91D1;&#x30CA;&#x30CE;&#x7C92;&#x5B50; (&#x91D1;) &#x306F; Hg(2+) &#x51DD;&#x96C6;&#x30BB;&#x30F3;&#x30B7;&#x30F3;&#x30B0;&#x5831;&#x544A;&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x6211;&#x3005; &#x5408;&#x6210; T SH &#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x306F; Au S &#x3068;&#x306E;&#x7D46;&#x306E;&#x91D1;&#x306E;&#x8868;&#x9762;&#x306B;&#x7C21;&#x5358;&#x306B;&#x7D50;&#x5408;&#x3059;&#x308B;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x3001;Hg(2+) &#x306F;&#x5F37;&#x3044;&#x89AA;&#x548C;&#x6027;&#x3068; T-Hg-T &#x306E;&#x8907;&#x5408;&#x4F53;&#x3092;&#x5F62;&#x6210;&#x3059;&#x308B;&#x3053;&#x3068;&#x306B;&#x3088;&#x308A;&#x9AD8;&#x9078;&#x629E;&#x3092;&#x8A8D;&#x8B58;&#x3067;&#x304D;&#x307E;&#x3059;&#x3002;T SH-&#x4FEE;&#x98FE;&#x91D1; (T S &#x91D1;) &#x30BB;&#x30F3;&#x30B5;&#x30FC;&#x306B;&#x3088;&#x3063;&#x3066;&#x3082; Hg(2+)&#x3001;T S, &#x3068;&#x8272;&#x3068;&#x7D2B;&#x5916;-&#x53EF;&#x8996;&#x5438;&#x53CE;&#x30B9;&#x30DA;&#x30AF;&#x30C8;&#x30EB;&#x306E;&#x91CD;&#x8981;&#x306A;&#x5909;&#x66F4;&#x306E;&#x7D50;&#x679C;&#x306E;&#x96C6;&#x8A08; TT Hg &#x8907;&#x5408;&#x4F53;&#x306E;&#x5F62;&#x6210;&#x3092;&#x8A98;&#x5C0E;&#x3057;&#x307E;&#x3059;&#x3002;&#x3057;&#x305F;&#x304C;&#x3063;&#x3066;&#x3001;&#x79C1;&#x305F;&#x3061;&#x30E1;&#x30BD;&#x30C3;&#x30C9; Hg(2+) &#x306E;&#x8FC5;&#x901F;&#x3001;&#x7C21;&#x5358;&#x304B;&#x3064;&#x4FE1;&#x983C;&#x6027;&#x306E;&#x9AD8;&#x3044;&#x30B9;&#x30AF;&#x30EA;&#x30FC;&#x30CB;&#x30F3;&#x30B0;&#x6C34;&#x6EB6;&#x6DB2;&#x3001;&#x9AD8;&#x3044;&#x611F;&#x5EA6;&#x3067;&#x4F7F;&#x7528;&#x3067;&#x304D;&#x307E;&#x3059; (2.8 nM) &#x3068;&#x7AF6;&#x5408;&#x3059;&#x308B; analytes &#x4EE5;&#x4E0A;&#x9078;&#x629E;&#x6027;&#x3002;&#x958B;&#x767A;&#x3057;&#x305F;&#x65B9;&#x6CD5;&#x306F;&#x3001;&#x6B63;&#x5E38;&#x306B; Hg(2+) &#x306E;&#x30B5;&#x30F3;&#x30D7;&#x30EB;&#x3067;&#x306F;&#x5B9F;&#x74B0;&#x5883;&#x30BB;&#x30F3;&#x30B7;&#x30F3;&#x30B0;&#x306B;&#x9069;&#x7528;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;

N - 1-(2-mercaptoethyl) &#x30C1;&#x30DF;&#x30F3;&#x4FEE;&#x98FE;&#x91D1;&#x30CA;&#x30CE;&#x7C92;&#x5B50;: &#x9AD8;&#x9078;&#x629E;&#x30FB;&#x9AD8;&#x611F;&#x5EA6;&#x6BD4;&#x8272; chemosensor Hg2 +&#x3002;

&#xC218;&#xC740; &#xC774;&#xC628; (Hg(2+)) &#xAC10;&#xC9C0; thymine (T)-&#xC26C;-functionalized &#xACE8;&#xB4DC; &#xB098;&#xB178; &#xC785;&#xC790; (AuNPs)&#xC758; Hg(2+) &#xC720;&#xB3C4; &#xC9D1;&#xACC4;&#xC5D0; &#xB530;&#xB77C; &#xBCF4;&#xACE0; &#xB418;&#xC5C8;&#xC2B5;&#xB2C8;&#xB2E4;&#xC5D0; &#xB300; &#xD55C; &#xC811;&#xADFC;. T SH ligands &#xC6B0;&#xB9AC;&#xAC00; &#xD569;&#xC131; &#xD558;&#xB294; Au S &#xBCF8;&#xB4DC;&#xB97C; &#xD1B5;&#xD574; Aunps&#xC758; &#xD45C;&#xBA74;&#xC5D0; &#xC27D;&#xAC8C; &#xACB0;&#xD569; &#xB420; &#xC218; &#xC788;&#xB2E4; &#xACE0; &#xAC15;&#xD55C; &#xC120;&#xD638;&#xB3C4; Hg TT &#xCF64;&#xD50C;&#xB809;&#xC2A4;&#xB97C; &#xD615;&#xC131; &#xD558; &#xC5EC; &#xB192;&#xC740; &#xC120;&#xD0DD;&#xB3C4; &#xAC00;&#xC9C4; hg(2+)&#xC744; &#xC778;&#xC2DD;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. AuNPs T-SH-functionalized (T-S-AuNPs) &#xC13C;&#xC11C; Hg(2+)&#xC758; &#xCD94;&#xAC00; &#xB530;&#xB77C; Hg TT &#xBCF5;&#xC7A1; &#xD55C; &#xD615;&#xC131; T-S-Aunps&#xC758; &#xC0C9;&#xC0C1;&#xACFC; &#xB9C8;&#xC8FC; UV &#xD761;&#xC218; &#xC2A4;&#xD399;&#xD2B8;&#xB7FC;&#xC758; &#xC911;&#xC694; &#xD55C; &#xBCC0;&#xD654;&#xC5D0; &#xACB0;&#xACFC;&#xC758; &#xC9D1;&#xACC4;&#xB97C; &#xC720;&#xB3C4; &#xD55C;&#xB2E4;. &#xB530;&#xB77C;&#xC11C;, &#xC6B0;&#xB9AC;&#xC758; &#xBC29;&#xBC95; &#xC218;&#xC131; &#xC194;&#xB8E8;&#xC158;&#xC5D0; hg(2+)&#xC758; &#xAE09;&#xC18D; &#xD55C; &#xAC04;&#xB2E8; &#xD558; &#xACE0; &#xC548;&#xC815;&#xC801;&#xC778; &#xC2EC;&#xC0AC;&#xC5D0; &#xB300; &#xD55C; &#xB192;&#xC740; &#xAC10;&#xB3C4;&#xC640; &#xC0AC;&#xC6A9;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; (2.8 nM)&#xACFC; &#xACBD;&#xC7C1; analytes &#xD1B5;&#xD574; &#xC120;&#xD0DD;&#xB3C4;. &#xAC1C;&#xBC1C;&#xB41C; &#xBC29;&#xBC95;&#xC740; &#xC2E4;&#xC81C; &#xD658;&#xACBD; &#xC0D8;&#xD50C;&#xC5D0;&#xC11C; hg(2+)&#xC758; &#xAC10;&#xC9C0;&#xC5D0; &#xC131;&#xACF5;&#xC801;&#xC73C;&#xB85C; &#xC801;&#xC6A9; &#xB429;&#xB2C8;&#xB2E4;.

N-1-(2-mercaptoethyl) &#xAE08; &#xB098;&#xB178; &#xC785;&#xC790;&#xC758; thymine &#xC218;&#xC815;: Hg2 +&#xC5D0; &#xB9E4;&#xC6B0; &#xC120;&#xD0DD;&#xC801;&#xC774; &#xACE0; &#xBBFC;&#xAC10;&#xD55C; &#xC0C9;&#xB3C4;&#xACC4; chemosensor.

Un enfoque para los iones de mercurio (Hg(2+)) detecci&oacute;n basada en la agregaci&oacute;n inducida por Hg(2+) de nanopart&iacute;culas de oro de timina (T) - SH - funcionalizado (AuNPs) se ha divulgado. Los T-SH ligandos que hemos sintetizados pueden acoplarse f&aacute;cilmente a la superficie del AuNPs a trav&eacute;s del v&iacute;nculo de Au-S y pueden reconocer Hg(2+) con alta selectividad formando un complejo T-Hg-T con gran afinidad. Para el sensor de AuNPs T-SH-funcionalizados (T-S-AuNPs), con adici&oacute;n de Hg(2+), la formaci&oacute;n del complejo T-Hg-T induce agregaci&oacute;n de T-S-AuNPs y resulta en un cambio significativo de color y espectros de absorci&oacute;n UV-Vis. Por lo tanto, nuestro m&eacute;todo puede utilizarse para la detecci&oacute;n r&aacute;pida, f&aacute;cil y confiable de Hg(2+) en soluci&oacute;n acuosa, con alta sensibilidad (2.8 nM) y selectividad sobre competencia analitos. El m&eacute;todo desarrollado se aplica con &eacute;xito a la detecci&oacute;n de Hg(2+) en muestras ambientales reales.

N - 1-(2-mercaptoethyl) modificaci&oacute;n de timina de nanopart&iacute;culas de oro: un chemosensor colorim&eacute;trico altamente selectivo y sensible para Hg2 +.

A novel monodisperse molecularly imprinted shell was prepared based on surface imprinted hollow vinyl-SiO2 particles and applied to selective recognition and adsorption of estradiol (E2). This method was carried out by introducing vinyltriethoxysilane to the surface of polystyrene (PS) spheres by a simple one-step modification, followed by dissolution to remove the PS cores, and then by copolymerization of functional monomers via surface imprinted on the hollow vinyl-SiO2 particles to prepare uniform E2-imprinted shells. Two interesting characteristics were found: first, the obtained hollow molecularly imprinted polymer shells (H-MIPs) had highly monodispersity, uniform spherical shape with a shell thickness of about 40 nm; and then, the method was simple, easy to operate by directing coating of a uniform shell on hollow particles via surface imprinting. The resultant H-MIPs demonstrated improvements in imprinting factor and binding kinetics, owing to the high selectivity to template molecules, surface imprinting technique and hollow porous structure. Furthermore, satisfactory recoveries of 97.0 and 94.8% with respective precisions of 2.5 and 2.7% were achieved by one-step extraction when H-MIPs were used for the preconcentration and selective separation of estradiol in milk samples at two spiked levels. The simple, effective H-MIPs based strategy provided new insights into the formation of various functionalized coating layers on different kinds of support materials with versatile potential applications.

Novel monodisperse molecularly imprinted shell for estradiol based on surface imprinted hollow vinyl-SiO₂ particles.

A facile strategy was developed to prepare molecular imprinting ratiometric fluorescence sensor for highly selective and sensitive detection of phycocyanin (PC) based on fluorescence resonance energy transfer (FRET), via a sol-gel polymerization process using nitrobenzoxadiazole (NBD) as fluorescent signal source. The ratio of two fluorescence peak emission intensities of NBD and PC was utilized to determine the concentration of PC, which could effectively reduce the background interference and fluctuation of diverse conditions. As a result, this sensor obtained high sensitivity with a low detection limit of 0.14 nM within 6 min, and excellent recognition specificity for PC over its analogues with a high imprinting factor of 9.1. Furthermore, the sensor attained high recoveries in the range of 93.8-110.2% at three spiking levels of PC, with precisions below 4.7% in seawater and lake water samples. The developed sensor strategy demonstrated simplicity, reliability, rapidity, high selectivity and high sensitivity, proving to be a feasible way to develop high efficient fluorescence sensors and thus potentially applicable for ultratrace analysis of complicated matrices.

Molecular imprinting ratiometric fluorescence sensor for highly selective and sensitive detection of phycocyanin.

A novel molecular imprinting-based turn-on ratiometric fluorescence sensor was constructed via a facile sol-gel polymerization for detection of 2,4-dichlorophenoxyacetic acid (2,4-D) on the basis of photoinduced electron transfer (PET) by using nitrobenzoxadiazole (NBD) as detection signal source and quantum dots (QDs) as reference signal source. With the presence and increase of 2,4-D, the amine groups on the surface of QDs@SiO2 could bind with 2,4-D and thereby the NBD fluorescence intensities could be significantly enhanced since the PET process was inhibited, while the QDs maintained constant intensities. Accordingly, the ratio of the dual-emission intensities of green NBD and red QDs could be utilized for turn-on fluorescent detection of 2,4-D, along with continuous color changes from orange-red to green readily observed by the naked eye. The as-prepared fluorescence sensor obtained high sensitivity with a low detection limit of 0.14μM within 5min, and distinguished recognition selectivity for 2,4-D over its analogs. Moreover, the sensor was successfully applied to determine 2,4-D in real water samples, and high recoveries at three spiking levels of 2,4-D ranged from 95.0% to 110.1% with precisions below 4.5%. The simple, rapid and reliable visual sensing strategy would not only provide potential applications for high selective ultratrace analysis of complicated matrices, but also greatly enrich the research connotations of molecularly imprinted sensors. 

A molecular imprinting-based turn-on Ratiometric fluorescence sensor for highly selective and sensitive detection of 2,4-dichlorophenoxyacetic acid (2,4-D).

Maintaining the redox balance of biological systems is a key point to maintain a healthy physiological environment. Excessive iron ions (Fe) can cause apoptosis, tissue damage and death. Fortunately, ascorbic acid (AA) as a reducing agent has been evaluated for the reduction of Fe. Moreover, AA plays an important role in relieving hypoxia-induced oxidative stress. Therefore, the real-time imaging of the Fe and AA fluctuations is important for understanding their biofunctions in cells and in vivo. In this work, we developed a fluorescent nanoprobe carbon dot-desferrioxamine B (CD-DB) by the conjugate connection of CDs and desferrioxamine B (a complexing agent for Fe) for the associated detection of Fe and AA. CD-DB exhibited excellent sensitivity and selectivity for the detection of Fe and AA. The nanoprobe CDs-DB@Fe obtained by the reaction of CD-DB and Fe was suitable for tracing the dynamic changes of AA in cells and in vivo. Therefore, CDs-DB@Fe was used for monitoring the fluctuation of AA in hypoxic cell models, hypoxic zebrafish models and liver ischemia mice models. These results exhibited the decrease in AA under hypoxic conditions because AA was consumed to neutralize free radicals and relieve hypoxia-induced oxidative stress damage. The ideal biocompatibility and low toxicity make our nanoprobe a potential candidate for the research of the physiological effects of AA in vivo.

A carbon dot-based fluorescent nanoprobe for the associated detection of iron ions and the determination of the fluctuation of ascorbic acid induced by hypoxia in cells and in vivo.

In this paper, we first proposed a novel hybrid three-dimensional (3D) printed and paper-based microfluidic platform and applied it for investigating the cell's apoptosis and intracellular cross-talk. The fabrication of a 3D-printed microfluidic chip is much easier than polydimethylsiloxane (PDMS) chip and can be applied in many common labs without soft lithogrophy fabrication equipment. Moreover, 3D printing can be perfectly combined with paper-based chips that can provide 3D scaffold for cell culture and analysis. In addition, these paper chips are disposable after use, greatly reducing the experimental cost. We integrated "Christmas Tree" structure with the top layer of the 3D-printed microfluidic chip to generate a continuous concentration gradient, and the bottom layer contained paper-based chips as cell culture area. The two-layer structure allows the concentration gradient forming layer to be separated from the cell culture layer, which can simplify the planting of cells in the microfluidic chip and make sure the cells stay in the culture chambers and don't clog the microfluidic channels. Applying this hybrid platform, we examined the effect of HS on cancer cells. Continuous exposure to a low concentration of HS inhibited cancer cell SMMC-7721 proliferation by inducing cell apoptosis. We also found that two gaseous molecules HS and NO have cross-talk in cancer cells; they formed bioactive intermediate polysulfides in cancer cells. It is expected that this novel hybrid 3D-printed and paper-based microfluidic platform will have widespread application prospects in cell investigation.

Qi Kang

National Microgravity Laboratory,
Institute of Mechanics,
National Microgravity Laboratory, Institute of Mechanics

Chinese Academy of Sciences

Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite

Qi Kang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}National Microgravity Laboratory,Institute of Mechanics,National Microgravity Laboratory, Institute of Mechanics

Chinese Academy of Sciences

Thermocapillary Convection Space Experiment on the SJ-10 Recoverable Satellite

National Microgravity Laboratory,
Institute of Mechanics,
National Microgravity Laboratory, Institute of Mechanics