Quantum-dot-modified electrode in combination with NADH-dependent dehydrogenase reactions for substrate analysis.
Quantum-dot-modified electrode in combination with NADH-dependent dehydrogenase reactions for substrate analysis.
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DOI：
10.1021/la902499e
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发表时间：
2010-01
期刊：
影响因子：
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通讯作者：
Kirsten Schubert;Waqas Khalid;Zhao Yue;W. Parak;F. Lisdat
中科院分区：
文献类型：
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作者：
Kirsten Schubert;Waqas Khalid;Zhao Yue;W. Parak;F. Lisdat
建立了一种用于烟酰胺腺嘌呤二核苷酸（nicotinamide adenine dinucleotide，NADH）检测的量子点电极系统。通过二硫醇化合物的化学吸附将胶体硒化镉/ZnS纳米晶体（量子点）附着到金上。电流信号可以通过照射量子点修饰的电极表面来触发。由于光激发，在量子点中产生电子-空穴对，其可以被检测为阳极或阴极光电流。通过光电流和石英晶体微天平（QCM）测量验证了纳米晶体的固定化。该研究表明，CdSe/ZnS量子点修饰的电极允许在20 μ M至2 mM的范围内的浓度依赖性NADH检测，已经在相当低的电位下（相对于Ag/AgCl，1 M KCl约0 V）。因此，这种电极可以与产生NADH的酶反应组合使用，用于生物催化剂的相应底物的光触发分析。可以表明，利用这种电极系统和光电流测量，葡萄糖检测是可行的。
A quantum dot-electrode system was developed which allows the sensitive detection of NADH (nicotinamide adenine dinucleotide). The colloidal semiconductive CdSe/ZnS nanocrystals (quantum dots) are attached to gold by chemisorption via a dithiol compound. The current signal can be triggered by illumination of the quantum-dot-modified electrode surface. Because of photoexcitation, electron-hole pairs are generated in the quantum dots, which can be detected as anodic or cathodic photocurrent. The immobilization of the nanocrystals is verified by amperometric photocurrent and quartz crystal microbalance (QCM) measurements. This study shows that CdSe/ZnS quantum dot-modified electrodes allow concentration dependent NADH detection in the range of 20 microM to 2 mM already at rather low potentials (around 0 V vs. Ag/AgCl, 1 M KCl). Therefore such electrodes can be used in combination with NADH-producing enzyme reactions for the light-triggered analysis of the respective substrates of the biocatalyst. It can be shown that glucose detection is feasible with such an electrode system and photocurrent measurements.