State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
Talanta. 2025 Jan 1;281:126868. doi: 10.1016/j.talanta.2024.126868. Epub 2024 Sep 13.
A novel fluorescence/colorimetric dual-mode sensor, based on enhancement of the oxidase-like activity of CeO/CuO nanozyme towards the oxidation of o-phenylenediamine (OPD) induced by thiourea (TU), has been proposed for TU detection. The catalytic activity enhancement on CeO/CuO can be attributed to the strong electron-donation ability of TU, which promoted hydroxyl radical generation and amplified OPD oxidization with enhanced dual-signal readout. By integrating a portable paper-chip and smartphone system, this CeO/CuO-OPD system achieved on-site visual colorimetric analysis of TU. The dual-mode sensor demonstrated high sensitivity and specificity in recognizing TU, with a detection limit (LOD) of 1.90 μM and a linear range (LR) 2.5-80 μM in fluorescent mode; as well as an LOD of 6.69 μM and an LR 10-250 μM in colorimetric mode. Furthermore, the CeO/CuO-TU-OPD system has been designed for dual-mode glutathione (GSH) detection with enhanced sensitivity, achieving an LOD of 0.19 μM and an LR 0.5-10 μM in fluorescent mode; as well as an LOD of 1.24 μM and an LR 1.25-25 μM in colorimetric mode. Additionally, GSH discrimination (fluorescent mode) was successfully achieved in different biological samples, showing good consistency with the standard method. The recoveries ranged from 96.8 % to 116.7 % in serum samples and from 97.3 % to 107.7 % in cell lysates, with RSDs less than 2 %. This work not only introduced a novel approach to enhance oxidase-like activity of nanozymes but also provided an efficient field-suitable tool for enhanced dual-mode response towards TU and GSH.
一种基于 CeO/CuO 纳米酶的过氧化物酶样活性增强的新型荧光/比色双通道传感器，用于检测硫脲（TU）诱导的邻苯二胺（OPD）的氧化。CeO/CuO 的催化活性增强归因于 TU 的强供电子能力，促进了羟基自由基的生成，并放大了 OPD 氧化，从而增强了双通道信号读取。通过整合便携式纸芯片和智能手机系统，该 CeO/CuO-OPD 系统实现了 TU 的现场可视化比色分析。双通道传感器在识别 TU 方面表现出高灵敏度和特异性，荧光模式下的检测限（LOD）为 1.90 μM，线性范围（LR）为 2.5-80 μM；比色模式下的 LOD 为 6.69 μM，LR 为 10-250 μM。此外，CeO/CuO-TU-OPD 系统被设计用于双模式谷胱甘肽（GSH）检测，具有增强的灵敏度，荧光模式下的 LOD 为 0.19 μM，LR 为 0.5-10 μM；比色模式下的 LOD 为 1.24 μM，LR 为 1.25-25 μM。此外，在不同的生物样品中成功实现了 GSH 的荧光模式区分，与标准方法具有良好的一致性。血清样品中的回收率范围为 96.8%-116.7%，细胞裂解液中的回收率范围为 97.3%-107.7%，RSD 小于 2%。这项工作不仅引入了一种增强纳米酶过氧化物酶样活性的新方法，而且为增强纳米酶对 TU 和 GSH 的双通道响应提供了一种有效的现场适用工具。
