Antifouling biosensors capable of preventing protein nonspecific adhesion in real human bodily fluids are highly sought-after for precise disease diagnosis and treatment. In this context, an enhanced split-type photoelectrochemical (PEC) aptasensor was developed incorporating a four-armed polyethylene glycol (4A-PEG) to construct a robust antifouling coating, enabling accurate and sensitive bioanalysis. The split-type PEC system involved the photoelectrode and the biocathode, effectively separating signal converter with biorecogniton events. Specifically, the TiO electrode underwent sequential modification with ZnInS (ZIS) and polydopamine (PDA) to form the PDA/ZIS/TiO photoelectrode. The cathode substrate was synthesized as a hybrid of -doped graphene loaded with Pt nanoparticles (NG-Pt), and subsequently modified with 4A-PEG to establish a robust antifouling coating. Following the anchoring of probe DNA (pDNA) on the 4A-PEG-grafted antifouling coating, the biocathode for model target of cancer antigen 125 (CA125) was obtained. Leveraging pronounced photocurrent output of the photoelectrode and commendable antifouling characteristics of the biocathode, the split-type PEC aptasensor showcased exceptional detection performances with high sensitivity, good selectivity, antifouling ability, and potential feasibility.

中文翻译：

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增强型分体式光电化学适体传感器，采用源自四臂聚乙二醇的坚固防污涂层

能够防止真实人体体液中蛋白质非特异性粘附的防污生物传感器在精确的疾病诊断和治疗中受到高度追捧。在此背景下，开发了一种增强型分体式光电化学（PEC）适体传感器，该传感器结合了四臂聚乙二醇（4A-PEG）来构建坚固的防污涂层，从而实现准确和灵敏的生物分析。分体式PEC系统涉及光电极和生物阴极，有效地将信号转换器与生物识别事件分开。具体来说，TiO电极经过ZnInS（ZIS）和聚多巴胺（PDA）的顺序修饰，形成PDA/ZIS/TiO光电极。阴极基底被合成为负载 Pt 纳米粒子 (NG-Pt) 的掺杂石墨烯的杂化物，随后用 4A-PEG 进行修饰以建立坚固的防污涂层。将探针DNA（pDNA）锚定在4A-PEG接枝的防污涂层上后，获得了癌抗原125（CA125）模型靶标的生物阴极。利用光电极显着的光电流输出和生物阴极值得称赞的防污特性，分体式PEC适体传感器表现出优异的检测性能，具有高灵敏度、良好的选择性、防污能力和潜在的可行性。