The biomarker CA15–3 plays a significant role in cancer diagnosis and therapeutic monitoring. In this study, a photoelectrochemical (PEC) immunosensor was designed using hexagonal ZnTiO/BiS heterojunction as the photoactive material, and ZnS@Au as a label for the detection antibody to amplify the signal. The hexagonal ZnTiO serves as the substrate material, providing a stable photocurrent response, while BiS forms a band-matching heterostructure with ZnTiO, facilitating the transfer of photogenerated electrons. Additionally, the narrow bandgap of BiS sensitizes the material, broadening its visible light response and further enhancing the photocurrent output. Moreover, square-shaped ZnS functionalized with Au NPs is employed as a quenching signal label, which effectively competed the photogenerated electrons and consumed electron donors in the electrolyte, thereby increasing the detection sensitivity. This sensor offers a broad detection range for CA15–3, from 0.001 U·mL to 1000 U·mL, with a detection limit of 0.0003 U·mL, illustrating its potential for precise and reliable cancer biomarker detection.

中文翻译：

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基于 Bi2S3 敏化六方 ZnTiO3 和 Au 功能化 ZnS 的高灵敏度 PEC 免疫传感器，用于 CA15–3 检测


生物标志物 CA15-3 在癌症诊断和治疗监测中发挥着重要作用。本研究设计了一种光电化学（PEC）免疫传感器，采用六方ZnTiO/BiS异质结作为光敏材料，ZnS@Au作为检测抗体的标记物来放大信号。六方ZnTiO作为衬底材料，提供稳定的光电流响应，而BiS与ZnTiO形成能带匹配异质结构，促进光生电子的转移。此外，BiS 的窄带隙使材料变得敏感，拓宽了其可见光响应并进一步增强了光电流输出。此外，采用Au NPs功能化的方形ZnS作为猝灭信号标记，有效竞争电解质中的光生电子并消耗电子供体，从而提高了检测灵敏度。该传感器为 CA15–3 提供了广泛的检测范围，从 0.001 U·mL 到 1000 U·mL，检测限为 0.0003 U·mL，说明了其精确可靠的癌症生物标志物检测的潜力。