Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University , Nanjing, 210023 Jiangsu, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Sep 24;6(18):16197-203. doi: 10.1021/am5043164. Epub 2014 Sep 8.
An innovative photoelectrochemical (PEC) biosensor platform was designed based on the in situ generation of CdS quantum dots (QDs) on graphene oxide (GO) using an enzymatic reaction. Horseradish peroxidase catalyzed the reduction of sodium thiosulfate with hydrogen peroxide to generate H2S, which reacted with Cd(2+) to form CdS QDs. CdS QDs could be photoexcited to generate an elevated photocurrent as a readout signal. This strategy offered a "green" alternative to inconvenient presynthesis procedures for the fabrication of semiconducting nanoparticles. The nanomaterials and assembly procedures were characterized by microscopy and spectroscopy techniques. Combined with immune recognition and on the basis of the PEC activity of CdS QDs on GO, the strategy was successfully applied to a PEC assay to detect carcinoembryonic antigen and displayed a wide linear range from 2.5 ng mL(-1) to 50 μg mL(-1) and a detection limit of 0.72 ng mL(-1) at a signal-to-noise ratio of 3. The PEC biosensor showed satisfactory performance for clinical sample detection and was convenient for determining high concentrations of solute without dilution. This effort offers a new opportunity for the development of numerous rapid and convenient analytical techniques using the PEC method that may be applied in the design and preparation of various solar-energy-driven applications.
基于酶反应在氧化石墨烯（GO）上原位生成硫化镉量子点（CdS QDs），设计了一种光电化学（PEC）生物传感器平台。辣根过氧化物酶（HRP）催化硫代硫酸钠与过氧化氢的还原反应生成 H2S，H2S 与 Cd（2+）反应形成 CdS QDs。CdS QDs 可以被光激发，产生增强的光电流作为读出信号。与半导体纳米粒子制备中不方便的预合成程序相比，这种策略提供了一种“绿色”的替代方法。纳米材料和组装程序通过显微镜和光谱技术进行了表征。该策略结合免疫识别，并基于 GO 上 CdS QDs 的 PEC 活性，成功应用于 PEC 测定法来检测癌胚抗原，并显示出从 2.5ng/mL 到 50μg/mL 的宽线性范围和 0.72ng/mL 的检测限，信噪比为 3。PEC 生物传感器在临床样品检测中表现出令人满意的性能，并且无需稀释即可方便地测定高浓度溶质。这项工作为使用 PEC 方法开发众多快速便捷的分析技术提供了新的机会，这些技术可能应用于各种太阳能驱动应用的设计和制备。
