The development of rapid screening sensing platforms to improve pre-screening mechanisms in community healthcare is necessary to meet the significant need for portable testing in biomarker diagnostics. Here, we designed a portable smartphone-based photoelectrochemical (PEC) immunoassay for carcinoembryonic antigen (CEA) detection using Cu-doped ultrathin porous BiWO (CuBWO) nanosheets as the photoactive material. The CuBWO nanosheets exhibit a fast photocurrent response and excellent electrical transmission rate under UV light due to their surface plasmon resonance effect (SPR). The method uses glucose oxidase-labeled secondary antibody as a signal indicator for sandwich-type immune conjugation. In the presence of the target CEA, the electrons and holes generated at the surface of the photo-excited ultrathin porous CuBWO were rapidly consumed by the production of HO from glucose oxidase oxidizing glucose, resulting in a weakened photocurrent signal. The photocurrent intensity increased logarithmically and linearly with increasing CEA concentration (0.02–50 ng mL), with a detection limit of 15.0 pg mL (S/N = 3). The system provides a broader idea for inferring the electron-hole transport mechanism in ultrathin porous nanosheet layer materials and developing efficient PEC sensors.

中文翻译：

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Cu掺杂多孔Bi2WO6纳米片的表面等离子体共振增强光电化学免疫分析

开发快速筛查传感平台以改善社区医疗保健中的预筛查机制对于满足生物标志物诊断中便携式测试的巨大需求是必要的。在这里，我们设计了一种基于智能手机的便携式光电化学（PEC）免疫测定法，使用掺杂铜的超薄多孔BiWO（CuBWO）纳米片作为光活性材料来检测癌胚抗原（CEA）。由于其表面等离子体共振效应（SPR），CuBWO 纳米片在紫外光下表现出快速的光电流响应和优异的电传输率。该方法使用葡萄糖氧化酶标记的二抗作为夹心型免疫偶联的信号指示剂。在目标CEA存在的情况下，光激发超薄多孔CuBWO表面产生的电子和空穴被葡萄糖氧化酶氧化葡萄糖产生的H2O迅速消耗，导致光电流信号减弱。光电流强度随着 CEA 浓度 (0.02–50 ng mL) 的增加呈对数和线性增加，检测限为 15.0 pg mL (S/N = 3)。该系统为推断超薄多孔纳米片层材料中的电子空穴传输机制和开发高效的 PEC 传感器提供了更广泛的思路。