Wang Huan, Yang Bo, Du Cuicui, Zheng Hejie, Zhang Xiaohua, Chen Jinhua
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P.R. China.
Small. 2025 Feb;21(7):e2409990. doi: 10.1002/smll.202409990. Epub 2025 Jan 6.
Nanozymes open up new avenues for amplifying signals in photoelectrochemical (PEC) biosensing, which are yet limited by the generated small-molecule signal reporters. Herein, a multifunctional nanoenzyme of Pt NPs/CoSAs@NC consisting of Co single atoms on N-doped porous carbon decorated with Pt nanoparticles is successfully synthesized for cascade catalytic polymerization of dopamine for constructing a highly sensitive photocurrent-polarity-switching PEC biosensing platform. Taking protein tyrosine phosphatase 1B (PTP1B) as a target model, Pt NPs/CoSAs@NC nanoenzymes are linked to magnetic microspheres via phosphorylated peptides. Upon dephosphorylation of PTP1B, Pt NPs/CoSAs@NC nanoenzymes with multiple enzyme-like activities, including peroxidase (POD)-like, catalase (CAT)-like, and oxidase (OXD)-like activities, are released and collected to induce the in situ cascade catalytic polymerization of dopamine on ZnCdS photoelectrode in the presence of HO. The generated polymer-molecule of polydopamine served as efficient signal reporter for simultaneously amplifying signal and switching photocurrent polarity, which not only improved the sensitivity but also enhanced the reliability. This biosensing platform is capable of sensitively quantifying PTP1B with ultralow detection limit (0.04 fM), wide linear range (0.1 fm-0.1 µm), and good applicability in complex biological samples. This work pioneers the utilization of nanozyme-based cascade catalytic polymerization strategy for improving sensitivity and reliability in biosensing technologies.
纳米酶为光电化学（PEC）生物传感中的信号放大开辟了新途径，但目前仍受限于所产生的小分子信号报告分子。在此，成功合成了一种由负载在氮掺杂多孔碳上的钴单原子与铂纳米颗粒组成的多功能纳米酶Pt NPs/CoSAs@NC，用于多巴胺的级联催化聚合，以构建高灵敏度的光电流极性转换PEC生物传感平台。以蛋白酪氨酸磷酸酶1B（PTP1B）为目标模型，通过磷酸化肽将Pt NPs/CoSAs@NC纳米酶连接到磁性微球上。当PTP1B去磷酸化时，具有多种类酶活性（包括类过氧化物酶（POD）、类过氧化氢酶（CAT）和类氧化酶（OXD）活性）的Pt NPs/CoSAs@NC纳米酶被释放并收集，以在HO存在的情况下诱导多巴胺在ZnCdS光电极上原位级联催化聚合。生成的聚多巴胺聚合物分子作为有效的信号报告分子，用于同时放大信号和转换光电流极性，这不仅提高了灵敏度，还增强了可靠性。该生物传感平台能够以超低检测限（0.04 fM）、宽线性范围（0.1 fM - 0.1 µm）灵敏地定量PTP1B，并且在复杂生物样品中具有良好的适用性。这项工作开创了利用基于纳米酶的级联催化聚合策略来提高生物传感技术的灵敏度和可靠性的先河。
