School of Resources and Environment, University of Jinan, Jinan 250022, PR China.
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Biosens Bioelectron. 2015 Apr 15;66:596-602. doi: 10.1016/j.bios.2014.12.002. Epub 2014 Dec 3.
A novel and simple photoelectrochemical (PEC) bioassay protocol for estradiol was proposed based on in situ generated CdS-enhanced TiO2 film via competitive strategy. The CdS was generated in situ by immediately dropping S(2-) onto the Cd(2+)-functionalized titanium phosphate nanoparticles (TiP@Cd(2+)). The TiO2 photoactive sensing film with countless active sites was obtained by calcination and further explored for estradiol (E2) capture. The TiP@Cd(2+) was used as labels and immobilized through affinity-specific binding with E2 on the surface of the electrode. Greatly enhanced sensitivity was achieved by using porous TiP nanoparticles as carriers to load a large amount of Cd(2+) and further for more CdS production through the S(2-) deposition. What's more, the photocurrent of CdS generated on the electrode surface could be significantly amplified by the coupling of CdS and TiO2, which could enhance the excitation and photo-to-electric conversion efficiency. Through the application of a competitive binding assay, the proposed biosensor showed high sensitivity with a detection limit down to 2pg/mL. This simple and fast PEC E2-sensing approach offers great promise to extend its application for the assay of small molecules of biomedical, food and environmental interest. Additionally, the strategy of employing in situ generated narrow-band gap semiconductors paves a new way for PEC sensing.
基于竞争策略，提出了一种新颖而简单的光电化学（PEC）雌二醇生物分析方法。通过立即将 S(2-)滴在磷酸钛纳米粒子（TiP@Cd(2+)）上原位生成 CdS，从而原位生成 CdS。通过煅烧获得具有无数活性位点的 TiO2 光活性传感薄膜，并进一步用于捕获雌二醇（E2）。TiP@Cd(2+) 用作标签，并通过与电极表面上的 E2 的亲和特异性结合而固定化。通过使用多孔 TiP 纳米粒子作为载体来负载大量的 Cd(2+)，并进一步通过 S(2-)沉积来产生更多的 CdS，从而实现了灵敏度的极大提高。更重要的是，通过 CdS 和 TiO2 的耦合，可以显著放大电极表面上生成的 CdS 的光电流，从而提高激发和光电转换效率。通过应用竞争结合分析，所提出的生物传感器具有高灵敏度，检测限低至 2pg/mL。这种简单快速的 PEC E2 传感方法有望扩展其在生物医学、食品和环境相关小分子分析中的应用。此外，采用原位生成的窄带隙半导体的策略为 PEC 传感开辟了新途径。
