This research was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Canada Research Chairs Program, and Simon Fraser University. This work made use of 4D LABS shared facilities supported by the Canada Foundation for Innovation (CFI), British Columbia Knowledge Development Fund (BCKDF) and Simon Fraser University.

NaYF 4 / YB 3+ / 어 3+ 업 컨버팅 나노 입자 (UCNP) 1. 합성 <ol><li> 다음으로 장치를 설정합니다 : <ol><li> 일반 교반 접시에 250 ml의 가열 맨틀을 놓고 열 커플에 맨틀을 연결합니다. </li><li> 적당한 클램프를 갖춘 가열 맨틀 상 자기 교반 바가 장착 된 250 mL의 둥근 바닥 플라스크를 배치했다. </li><li> 환저 플라스크의 목의 왼쪽에 공기 어댑터를 연결하고 플라스틱 배관과 쉬 렌크 라인이 공기 어댑터를 연결한다. </li><li> 환저 플라스크의 오른쪽 목 유리 어댑터를 장착하고, 유리 어댑터에 온도계 어댑터를 고정한다. 온도계 어댑터를 통해 플라스크에 온도 프로브를 삽입하고 열전대에이 연결합니다. </li><li> 환저 플라스크의 목 중간 증류 헤드를 부착. 증류 머리 꼭대기에 마개를 놓습니다. 진공 distillat이어서 응축기 헤드를 연결이온 어댑터 및 50 ㎖ 둥근 바닥 플라스크. 플라스틱 튜브를 통해 버블로 진공 증류 어댑터를 연결합니다. </li></ol></li><li> 이트륨 아세테이트 1.17 g (3.9 mmol)을, 이테르븀 아세테이트 0.439 g 및 에르븀 아세테이트 0.0727 g (0.1 밀리몰)을 달아 라운드 반응 바닥 플라스크에 배치합니다. </li><li> 올레산 30 mL 및 눈금 실린더를 사용하여 플라스크에 옥타의 75 ML을 추가합니다. </li><li> 메탄올 5 mL를 더 올레산과 옥타는 반응 플라스크의 측면에 붙어 있지 않은지 확인하기 위해 사용하는 둥근 바닥 플라스크에 반응의 측면을 씻어. </li><li> 이중 매니 폴드 쉬 렌크 라인에 반응 플라스크를 연결하고, 질소 라인에 연결된 반응 플라스크를 유지 해당 밸브를 반전. </li><li> 열전대를 켜고 80 ° C의 온도로 설정하고,이 온도로 서서히 가열 시스템. 모든 출발 물질이 용해 된 후 80 ℃로하고, 가열 맨틀을 제거하고, 반응을 허용30 ℃로 냉각. </li><li> 온도가 30 ℃에 도달하면, 증류 머리를 벗어 중간 목에 왼쪽 목에서 공기 어댑터를 전환하고 마개를 왼쪽 목을 닫습니다. 천천히 진공 라인에 질소 라인에서 쉬 렌크 라인에 밸브를 돌려서 반응 플라스크에 진공을 소개한다. 저비점 성분은 모두이 지점에서 반응으로부터 인출한다. </li><li> 이 솔루션은 버블 링을 중지하면, 5 ℃ / min의 속도로 115 ℃까지 온도를 올립니다. </li><li> 온도가 115 ° C에 도달하면, 15 분 동안이 온도를 유지 한 다음, 가열 맨틀을 제거하고 50 ℃까지 반응물을 냉각. 그 후, 신속하게 중간 목과 왼쪽 머리에 공기 어댑터에 증류 머리를 다시 연결하여 원래 형태로 설정 전환합니다. </li><li> 냉각 과정 중에 NaOH를 0.74 g (12.5 mmol) 및 NH 4 F의 0.50 g (20.0 밀리몰)의 무게, 그 용해초음파 처리하여 50 ml의 메탄올에. </li><li> 초음파 처리 후, 둥근 바닥 플라스크에, 반응 용액을 부어 메탄올 5ml를 플라스크의 측면을 헹군다. </li><li> 30 분 동안 50 ℃에서 교반 솔루션을 남겨주세요. </li><li> 메탄올을 증류 75 ° C까지 온도를 높입니다. </li><li> 필요하다면 증류 동안 수집 플라스크를 비우고. 증류가 완료되면, 가능한 한 빨리 질소 보호 하에서 300 ℃로 반응을 가열. </li><li> 온도가 300 ° C에 도달하면, 1 시간 동안이 온도를 유지한다. 필요한 경우, 온도를 유지하기 위해 알루미늄 호일로 설정 커버. 이어서, 열원을 제거하고, 반응물을 실온으로 냉각되도록. </li><li> 실온까지 냉각되면, 세 원심 분리 튜브 (50 ㎖ 튜브, 각각의 튜브 당 약 35 ml의 용액)으로 균일 용액을 분리하고, 50ml로 가기까지 튜브를 무수 에탄올을 사용하여 스케일. 원심 분리기 모든 T그는 15 분 동안 3,400 XG에 튜브. 원심 분리 후, UCNPs는 백색 침전물로서 튜브 측에서 관찰한다. </li><li> 뜨는을 취소하고 헥산 (각 관마다 헥산 7.5 ml)에 UCNPs 펠릿을 재 분산 한 후 50 ml의 규모에 에탄올로 튜브를 맨. 원심 분리기 튜브 다시 15 분 동안 3,400 XG에. </li><li> 원심 분리가 완료된 후, 상층 액을 제거하고 추가로 사용하기에 클로로포름 30 ㎖에 재 분산을 고체 UCNPs. </li></ol> 유기 염료 분자와 업 컨버팅 나노 입자를 포함하는 2의 조립 물 산성 Nanoassemblies <ol><li> 자기 교반 바가 장착 된 섬광 바이알에 클로로포름 (3)의 3 mL의 폴리 (스티렌 - 말레 산 무수물 ALT), 25 mg의 (0.0147 밀리몰) (PSMA)을 녹인다. 이 수량은 여러 실험 후 최적의 양이다. </li><li> 상향 변환의 250 μL (47 ㎎ / ㎖)를 추가하면 scinti에 클로로포름 원액을 나노 입자llation 유리 병. </li><li> 바이알을 캡핑하고 자기 교반 플레이트에 배치하고, 2 시간 동안 실온에서 용액을 교반 하였다. </li><li> 2,070의 폴리 에테르 아민 160 mg의 (0.0773 밀리몰)을 달아 클로로포름 1 ㎖에 용해. 그런 다음 피펫을 사용하여 한 부분에 섬광 유리 병에이 솔루션을 추가 할 수 있습니다. 이 솔루션은 PSMA에 무수 그룹과 2070 아민 폴리 에테르의 반응을 나타내는 엷은 황색에 켜집니다. </li><li> 실온에서 하룻밤 솔루션을 저어 계속합니다. </li><li> 1 시간 동안 생성 된 용액을 교반하고 유기 색소 분자의 적절한 양을 한번에 측정하는 섬광 바이알로 분배. <ol><li> 샘플 TPP-NP (nanoassembly 폴리머 쉘, 테트라 페닐 포르피린 및 상향 변환 나노 입자를 포함)의 경우, 직접 섬광 유리 병에 테트라 페닐 포르피린의 1 mg을 추가합니다. 샘플 DAE-UCNP (들어 nanoassembly 폴리머 쉘, 디아 릴에 텐 분자 및 상향 변환 나노 입자를 포함하는S), 각각의 디아 릴에 텐 분자의 양이 2 × 10-7 몰이다. 반응 용액에 두 디아 릴에 텐 분자를 추가합니다. 두 디아 릴에 텐 분자의 볼륨은 다음과 같습니다 DAE-1O (1.8 mM)을 111 μL 및 DAE-2O (1.6 mM)을 125 μl를. </li></ol></li><li> 회전 증발기를 사용하여 감압 하에서 클로로포름 용매를 제거 후, 유백색 현탁액이 형성 될 때까지 초음파 처리 바이알, 섬광 바이알에 3 ㎖ (11 산도 ≈) M 수성 NaOH 0.001 추가. </li><li> 다시 회전 증발기에 병을 놓고 현탁액 맑은 용액로 전환 될 때까지주의 깊게 남아있는 클로로포름을 제거합니다. </li><li> 다음 25 분 동안 20,600 XG에서 솔루션을 원심 분리, 두 개의 1.5 ML 원뿔 원심 분리 튜브에 섬광 유리 병에서 솔루션을 전송합니다. </li><li> 상층 액을 제거하고, 두 개의 튜브 (튜브 당 1.5 mL)에 탈 H 2 O 3 ㎖의 총을 추가 펠릿을 재 분산하기 위해 튜브를 초음파 처리탈 H 2 O에 </li><li> 25 분 동안 20,600 XG에서 다시 두 개의 튜브를 원심 분리기. </li><li> 상층 액을 버리고, 그 다음 두 개의 튜브 (튜브 당 1.5 mL)에 탈 H 2 O 3 ㎖의 총을 추가합니다. 탈 H 2 O에 펠렛을 재 분산하는 튜브를 초음파 처리 </li><li> 상기 테스트에 대한 최종 샘플을 얻기 위해 0.2 ㎛의 주사기 필터로 나노 입자의 수​​성 분산액 샘플을 필터링. </li></ol>

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C., Barker, M., Wilson, D., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+"Plug-and-Play"+Method+to+Prepare+Water-Soluble+Photoresponsive+Encapsulated+Upconverting+Nanoparticles+Containing+Hydrophobic+Molecular+Switches.">A "Plug-and-Play" Method to Prepare Water-Soluble Photoresponsive Encapsulated Upconverting Nanoparticles Containing Hydrophobic Molecular Switches.</a> Chem. Mater. 25 (12), (2013).</li><li>Wu, T., Kaur, S., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energy+transfer+between+amphiphilic+porphyrin+polymer+shells+and+upconverting+nanoparticle+cores+in+water-dispersible+nano-assemblies.">Energy transfer between amphiphilic porphyrin polymer shells and upconverting nanoparticle cores in water-dispersible nano-assemblies.</a> Org. Biol. Chem. 13, 2317-2322 (2015).</li><li>Irie, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photochromism:+Memories+and+Switches+Introduction.">Photochromism: Memories and Switches Introduction.</a> Chem. Rev. 100 (5), 1683-1684 (2000).</li></ol>

The authors have nothing to disclose.

이 프로토콜에 따라 합성 된 나노 입자는 그들이 α-4 NaYF 호스트 격자 구조를 갖는 구형 입자로 분류 될 수 약 22.5 내지. (26, 27)를 중심으로 20 ~ 25 nm 내지 크기 분포를 갖는다. 이 프로토콜에서 두 가지 중요한 단계가 있습니다. UCNP 합성에서, 입자 크기의 분포가 좁은 보장하기 위해 가능한 한 정확한 가열 온도 및 시간을 유지하는 것이 중요하다. 잘 분산 된 크기와 양호한 형태의 ?...

현재 바이오 조영제 새로운 유형의 개발이 요구 여전히 존재한다. 많은 신규 형광 프로브는 잘 문서화되어있다. 1-6 그러나, 이미지 해상도에서 상당한 개선이 과제로 남아. 7 한 실용적인 방법은 직접 &quot;광&quot;방출 상태와 &#39;어두운&#39;켄칭 상태 사이에서 형광 프로브를 변조하는 것이다. 8-12이 특별한 방법은 유도 방출 고갈과 같은 기술을 개발하기 위해 적용되어왔다 (STED) 현미경 (13) 및 확률 광학 재구성 ​​현미경 (STORM). 14 형광을 조절하는 또 다른 방법은 형광 프로브와 함께 커플 감응성 발색단이다. 15,16 이성질체 중 하나만이 효율적인 에너지 전달 셉터로서 작용할 수 개의 이성체 간의 감응성 발색단 토글, 일부터 형광 소광에 대한 제어를 허용포스터 공명 에너지 전달 (FRET) 및 다른 메커니즘을 통해 전자 프로브. 결과는 발광 상태의 생성과 상이한 파장의 광 감응성에 발색단의 노출에 의해 번갈아 수 켄칭 상태이다. 광 감응성 디아 릴에 텐 발색단 가역적 무색 링 공개 이성질체 및 UV 및 가시광 조사에 의해 착색 폐환 체 사이에 전환 할 수있다. 17-19 폐환 체 확인의 두 이성체와 동조 흡수 스펙트럼의 열 안정성 diarylethenes 좋은 후보들을 제어 FRET 수용체로. 20-23 란탄 도핑 NaYF 4 상향 변환 된 나노 입자는 생체 이미징에 유용하다. 이러한 나노 입자 (24)는 근적 외광을 흡수하고 가시 스펙트럼의 여러 영역에서 발광한다. 디아 릴에 텐 광 감응성 발색단 및 나노 입자를 결합하여 형광 변조로서는 미리되었습니다viously 우리 그룹에 의해보고. 25-27하지만, 각 실시 예에 설명 된 시스템보다 다양한 시스템의 개발을 복잡하게하는 나노 입자의 표면에 부착하는 diarylethenes 합성 추가적인 수정이 필요했다. 여기서 우리는 자기 조립 전략을 사용하여 수분 산성 유기 색소 분자와 광 감응성 상향 변환하는 나노 입자를 제조하는 간단한 &quot;플러그 앤 플레이&quot;방법을 보여준다. 중합체의 선택; 2070 아민 폴리 (스티렌 - 고도 - 말레 산 무수물) 및 폴리 에테르는 소수성과 친수성 환경을 모두 제공합니다. 고분자의 친수성 ​​영역은 수용성을 유지하기위한 중요한 반면 고분자 도움의 소수성 부분은 함께 일반적으로 불용성 유기 분자 및 상향 변환 나노 입자를 개최합니다. 먼저 열 핵 방법에 의해 상향 변환 된 나노 입자의 합성을 설명한다. 그런 다음, 우리는 호를 새삼 느끼게 될 것이다유기 분자 및 상향 변환 나노 입자는 폴리머 외피의 소수성 영역 내에 캡슐화 단순히 편리한 워크 - 업 과정이어서 업 컨버팅 나노 입자, 중합체 및 다른 유기 염료 분자의 용액을 공동 교반하여 수성 매체에 안정적으로 유지된다 w. 우리는 또한 외부 광 조사를 사용하여 어셈블리의 형광 방출을 조절하는 방법을 보여줍니다. 우리는 수분 산성 nanoassemblies 확장 계속하도록이 &quot;플러그 앤 플레이&quot;를 사용하는 방법의 범위를 예상하고있다.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>yttrium acetate</td>
			<td>sigma</td>
			<td>326046</td>
			<td>Yttrium(III) acetate hydrate</td>
		</tr>
		<tr>
			<td>ytterbium acetate</td>
			<td>sigma</td>
			<td>544973</td>
			<td>&#160;Ytterbium(III) acetate hydrate&#160;</td>
		</tr>
		<tr>
			<td>erbium acetate</td>
			<td>sigma</td>
			<td>325570</td>
			<td>Erbium(III) acetate hydrate</td>
		</tr>
		<tr>
			<td>oleic acid</td>
			<td>sigma</td>
			<td>75096</td>
			<td>analytical standard</td>
		</tr>
		<tr>
			<td>octadecene</td>
			<td>sigma</td>
			<td>O806&#160;</td>
			<td>Technical grade&#160;</td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td></td>
			<td>S5881&#160;</td>
			<td>reagent grade</td>
		</tr>
		<tr>
			<td>NH4F</td>
			<td></td>
			<td>216011</td>
			<td>ACS reagent</td>
		</tr>
		<tr>
			<td>poly(styrene-alt-maleic anhydride)</td>
			<td>sigma</td>
			<td>4422699</td>
			<td>Average Mn= 1700</td>
		</tr>
		<tr>
			<td>JeffAmine 2070</td>
			<td>Huntsman</td>
			<td>M-2070</td>
			<td></td>
		</tr>
		<tr>
			<td>Varian Carry 300</td>
			<td>Agilent</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>JDSU NIR laser</td>
			<td>JSDU</td>
			<td>L4-9897510-100M</td>
			<td>980 nm diode laser</td>
		</tr>
	</tbody>
</table>

a 'plug and play' method to create water-dispersible nanoassemblies containing an amphiphilic polymer, organic dyes and upconverting nanoparticles

In this protocol, we first describe a procedure to synthesize lanthanide doped upconverting nanoparticles (UCNPs). We then demonstrate how to generate amphiphilic polymers in situ, and describe a protocol to encapsulate the prepared UCNPs and different organic dye molecules (porphyrins and diarylethenes) using polymer shells to form stable water-dispersible nanoassemblies. The nanoassembly samples containing both the UCNPs and the diarylethene organic dyes have interesting photochemical and photophysical properties. Upon 365 nm UV irradiation, the diarylethene group undergoes a visual color change. When the samples are irradiated with visible light of another specific wavelength, the color fades and the samples return to the initial colorless state. The samples also emit visible light from the UCNPs upon irradiation with 980 nm near-infrared light. The emission intensity of the samples can be tuned through alternate irradiation with UV and visible light. Modulation of fluorescence can be performed for many cycles without observable degradation of the samples. This versatile encapsulation procedure allows for the transfer of hydrophobic molecules and nanoparticles from an organic solvent to an aqueous medium. The polymer helps to maintain a lipid-like microenvironment for the organic molecules to aid in preservation of their photochemical behavior in water. Thus this method is ideal to prepare water-dispersible photoresponsive systems. The use of near-infrared light to activate upconverting nanoparticles allows for lower energy light to be used to activate photoreactions instead of more harmful ultraviolet light.

흡수 스펙트럼 및 광 발광 스펙트럼을 샘플 DAE-UCNP 수집 하였다. 흡수 스펙트럼은 폐쇄 디아 릴에 텐 발색단 및 상향 변환 된 나노 입자 사이의 스펙트럼 중첩을 비교하는 데 사용된다. 샘플 (TPP-UCNP 모두와 UCNP-DAE)의 사진은 또한 수성 상에 양친 매성 고분자 쉘 내에 위치되는 유기 염료 분자와 나노 입자를 상향 변환, 성공적으로 캡슐화를 보여주기 위해 포함되었다. 광화학 및 형광의 변조는 다른 ...

Watch this Scientific Journal Video about A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles at JoVE.com

A &#039;Plug and Play&#039; Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

Organic dye molecules and oleic acid coated upconverting nanoparticles are not water-soluble. This protocol describes a &#8216;plug and play&#8217; method that enables the transfer of organic dye molecules and upconverting particles from their initial hydrophobic solvent to water.

&#39;플러그 앤 플레이&#39;방법은 양친 매성 고분자, 유기 염료 및 업 컨버팅 나노 입자를 포함하는 수분 산성 Nanoassemblies 만들기

In this protocol, we first describe a procedure to synthesize lanthanide doped upconverting nanoparticles (UCNPs). We then demonstrate how to generate ...

a-plug-play-method-to-create-water-dispersible-nanoassemblies

Research

JoVE Journal

Chemistry

A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

9.8K 조회수.  Simon Fraser University. Organic dye molecules and oleic acid coated upconverting nanoparticles are not water-soluble. This protocol describes a ‘plug and play’ method that enables the transfer of organic dye molecules and upconverting particles from their initial hydrophobic solvent to water. 

비디오: A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The analysis of volatile and oxidation sensitive compounds by mass spectrometry is not easily achieved, as all state-of-the-art mass spectrometric methods require at least one sample preparation step, e.g., dissolution and dilution of the analyte (electrospray ionization), co-crystallization of the analyte with a matrix compound (matrix-assisted laser desorption/ionization), or transfer of the prepared samples into the ionization source of the mass spectrometer, to be conducted under atmospheric conditions. Here, the use of a sample inlet system is described which enables the analysis of volatile metal organyls, silanes, and phosphanes using a sector field mass spectrometer equipped with an electron impact ionization source. All sample preparation steps and the sample introduction into the ion source of the mass spectrometer take place either under air-free conditions or under vacuum, enabling the analysis of compounds highly susceptible to oxidation. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes, which have to be handled using inert conditions, such as the Schlenk technique. The principle of operation is presented in this video.

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.

콜드 입구 시스템 및 전자 충격 질량 분석법을 사용하여 휘발성 및 산화에 민감한 화합물의 분석

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The ...

연구

화학

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

기능화의 합성 및 특성 금속 - 유기 프레임 워크

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

주변 조건에 따라 금 나노 입자의 안정 올리고머 클러스터의 크기 제어 합성을위한 간단한 방법

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

An ELISA Based Binding and Competition Method to Rapidly Determine Ligand-receptor Interactions

A comprehensive understanding of signaling pathways requires detailed knowledge regarding ligand-receptor interaction. This article describes two fast and reliable point-by-point protocols of enzyme-linked immunosorbent assays (ELISAs) for the investigation of ligand-receptor interactions: the direct ligand-receptor interaction assay (LRA) and the competition LRA. As a case study, the ELISA based analysis of the interaction between different lambda interferons (IFNLs) and the alpha subunit of their receptor (IL28RA) is presented: the direct LRA is used for the determination of dissociation constants (KD values) between receptor and IFN ligands, and the competition LRA for the determination of the inhibitory capacity of an oligopeptide, which was designed to compete with the IFNLs at their receptor binding site. Analytical steps to estimate KD and half maximal inhibitory concentration (IC50) values are described. Finally, the discussion highlights advantages and disadvantages of the presented method and how the results enable a better molecular understanding of ligand-receptor interactions.

The presented protocols describe two enzyme-linked immunosorbent assay (ELISA) based techniques for the rapid investigation of ligand-receptor interactions: The first assay allows the determination of dissociation constant between ligand and receptor. The second assay enables a rapid screening of blocking peptides for ligand-receptor interactions.

ELISA 기반 바인딩과 경쟁 방법은 신속 리간드 - 수용체 상호 작용을 확인하는 방법

A comprehensive understanding of signaling pathways requires detailed knowledge regarding ligand-receptor interaction. This article describes two fast and ...

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ethylene-propylene rubber, grafted with maleic anhydride, is thermo-reversibly cross-linked in two steps. The pending anhydride moieties are first modified with furfurylamine to graft furan groups to the rubber backbone. These pendant furan groups are then cross-linked with a bis-maleimide via a Diels-Alder coupling reaction. Both reactions can be performed under a broad range of experimental conditions and can easily be applied on a large scale. The material properties of the resulting Diels-Alder cross-linked rubbers are similar to a peroxide-cured ethylene/propylene/diene rubber (EPDM) reference. The cross-links break at elevated temperatures (&#62; 150 &#176;C) via the retro-Diels-Alder reaction and can be reformed by thermal annealing at lower temperatures (50-70 &#176;C). Reversibility of the system was proven with infrared spectroscopy, solubility tests and mechanical properties. Recyclability of the material was also shown in a practical way, i.e., by cutting a cross-linked sample into small parts and compression molding them into new samples displaying comparable mechanical properties, which is not possible for conventionally cross-linked rubbers.

A simple two-step approach involving rubber modification and cross-linking yields fully reworkable, elastic rubber products.

열 가역적 가교 고무 통해 딜스 - 알더 화학의 준비 및 등록

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ...

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [125I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified 125I-labeled azide (1) was obtained with high radiochemical yield (75 &plusmn; 10%, n = 8) and excellent radiochemical purity (&gt;99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the 125I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

A detailed procedure for the synthesis of a 125I-labeled azide and the radiolabeling of dibenzocyclooctyne (DBCO)-group-conjugated, 13-nm-sized gold nanoparticles using a copper-free click reaction is described.

를 사용하여 금 나노 입자의 효율적인 방사성 표지를위한 최적화 된 프로토콜<sup&gt; (125)</sup&gt; I-표시 아 지드 보철 그룹

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient ...

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites. Those polymerizable groups can address further polymerization of styrene to produce a hybrid nanomaterial containing PS chains grafted to the nanotube sidewalls. The polymer-graft content, amount of silylated methacrylic moieties introduced and hydroxylation modification of the nanotubes are identified and quantified by Thermogravimetric Analysis (TGA). The presence of reactive functional groups hydroxyl and silylated methacrylate are confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Polystyrene-grafted carbon nanotube solutions in tetrahydrofuran (THF) provide wall-to-wall collinearly self-assembled nanotubes when cast samples are analyzed by transmission electron microscopy (TEM). Those self-assemblies are not obtained when suitable blanks are similarly cast from analogous solutions containing non-grafted counterparts. Therefore, this method enables the modification of the nanotube anisotropic patchiness at the sidewalls which results into spontaneous auto-organization at the nanoscale.

A procedure for the synthesis of polystyrene-grafted multiwalled carbon nanotubes using successive chemical modification steps to selectively introduce the polymer chains to the sidewalls and their self-assembly via anisotropic patchiness is presented.

자기 집합에 있도록 폴리스 티 렌과 이방성 Patchiness Multiwalled 탄소 나노튜브를 접목

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a ...

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables the acquisition of photoluminescence spectra covering the time regime from nanoseconds up to 0.1 s. This enables us to follow the changes in the intensity (decay) and emission of the spectra over time. Using this method, it is possible to study diverse photophysical phenomena, such as the emission of phosphorescence, and the contributions of prompt and delayed fluorescence in molecules showing thermally activated delayed fluorescence (TADF). Remarkably, all spectra and decays are obtained in a single experiment. This can be done for solids (thin film, powder, crystal) and liquid samples, where the only limitations are the spectral sensitivity of the camera and the excitation wavelength (532 nm, 355 nm, 337 nm, and 266 nm). This technique is, thus, very important when investigating the excited state dynamics in organic emitters for their application in organic light-emitting diodes and other areas where triplet harvesting is of paramount importance. Since triplet states are strongly quenched by oxygen, emitters with efficient TADF luminescence, or those showing room temperature phosphorescence (RTP), must be correctly prepared in order to remove any dissolved oxygen from solutions and films. Otherwise, no long-lived emission will be observed. The method of degassing solid samples as presented in this work is basic and simple, but the degassing of liquid samples creates additional difficulties and is particularly interesting. A method of minimizing solvent loss and changing the sample concentration, while still enabling to remove oxygen in a very efficient and a repeatable manner, is presented in this work.

Here, we present a method of the spectroscopic characterization of organic molecules by means of time-resolved photoluminescence spectroscopy on the nanosecond-to-millisecond timescale in oxygen-free conditions. Methods to efficiently remove oxygen from the samples and, thus, limit luminescence quenching are also described.

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables ...

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule on the vibrational level of energy. Raman and IR spectroelectrochemistry can be used for advanced characterization of the structural changes in the organic electroactive compounds. Here, the step-by-step analysis by means of Raman and IR spectroelectrochemistry is shown. Raman and IR spectroelectrochemical techniques provide complementary information about structural changes occurring during an electrochemical process, i.e. allows for the investigation of redox processes and their products. The examples of IR and Raman spectroelectrochemical analysis are presented, in which the products of the redox reactions, both in solution and solid state, are identified.

A protocol of step-by-step Raman and IR spectroelectrochemical analysis is presented.

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

O-Carboxyanhydrides Ni/Zn 단지 중재의 Photoredox 반지 개통 중 합 제어

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...