Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
Biosens Bioelectron. 2012 Oct-Dec;38(1):43-9. doi: 10.1016/j.bios.2012.04.040. Epub 2012 May 11.
A new, highly sensitive and selective biosensor for the photoelectrochemical (PEC) detection of organophosphate pesticides (OPs) has been developed, whereby newly synthesized crossed bismuth oxyiodide (BiOI) nanoflake arrays (BiOINFs) are fabricated as a photoactive electrode via a successive ionic layer adsorption and reaction (SILAR) approach. The smart integration of BiOINFs with biomolecules acetylcholinesterase (AChE) yields a novel AChE-BiOINFs hybrid, constructing a three-dimensional (3D) porous network biosensing platform. The composition and surface structure of the sensor were carefully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and various electrochemical techniques. Such interlaced network architectures, providing better mass transport and allowing more AChE loading per unit area, as well as the intrinsically strong visible light-harvesting effect from BiOI, greatly facilitate the PEC responses. On the basis of the effect of OPs on the photocurrent of AChE-BiOINFs/ITO, a highly sensitive visible light-activated photoelectrochemical biosensor was developed for biosensing OPs. The conditions for OPs detection were optimized by using methyl parathion (MP) as a model OP compound. Under the optimized experimental conditions, our results show that such a newly designed AChE-BiOINFs/ITO photoactive electrode provides remarkably improved sensitivity and selectivity for the biosensing of OPs. The detection limit was found to be as low as about 0.04 ng mL(-1) (S/N=3). Toward the goal for practical applications, the resulting sensor was further evaluated by monitoring MP in spiked vegetable samples, showing fine applicability for the detection of MP in real samples.
一种新的、高灵敏度和选择性的光电化学（PEC）检测有机磷农药（OPs）的生物传感器已经开发出来，其中新合成的交叉铋氧碘化物（BiOI）纳米片阵列（BiOINFs）通过连续离子层吸附和反应（SILAR）方法被制造为光活性电极。BiOINFs 与生物分子乙酰胆碱酯酶（AChE）的智能集成产生了一种新型的 AChE-BiOINFs 杂化体，构建了一个三维（3D）多孔网络生物传感平台。传感器的组成和表面结构通过 X 射线衍射（XRD）、扫描电子显微镜（SEM）和各种电化学技术进行了仔细的表征。这种交错的网络结构提供了更好的质量传输，允许每单位面积更多的 AChE 负载，以及 BiOI 固有的强可见光收集效应，极大地促进了 PEC 响应。基于 OPs 对 AChE-BiOINFs/ITO 光电流的影响，开发了一种基于可见光源的高灵敏度光电化学生物传感器用于 OPs 的生物传感。通过使用甲基对硫磷（MP）作为模型 OP 化合物来优化 OPs 检测条件。在优化的实验条件下，我们的结果表明，这种新设计的 AChE-BiOINFs/ITO 光活性电极对 OPs 的生物传感提供了显著提高的灵敏度和选择性。检测限被发现低至约 0.04ng mL(-1)（S/N=3）。为了实现实际应用的目标，进一步通过在掺杂蔬菜样品中监测 MP 来评估所得传感器，显示出对实际样品中 MP 检测的良好适用性。
