Platinum Nanoparticles Loaded in Polydopamine-Modified Porous Coordination Network-224 with Peroxidase-Like Activity for Sensitive Glutathione Detection

The content of glutathione in the human body is crucial to human health, so a convenient and efficient method is needed to detect it. Herein, porous coordination network-224 (PCN-224) was modified by polydopamine to prepare polydopamine-modified PCN-224 (PCN-224-PDA) to improve the water dispersibility of the PCN-224. Monodispersed platinum nanoparticles were loaded into the PCN-224-PDA to prepare PCN-224-PDA-Pt. The PCN-224-PDA-Pt showed high peroxidase-like catalytic activity, and its catalytic activity was affected by pH and temperature. The PCN-224-PDA-Pt almost had no hemolysis of red blood cells. In addition, the PCN-224-PDA-Pt showed high affinity for 3,3′,5,5′-tetramethylbenzidine and catalytic efficiency in kinetic studies, and the type of reactive oxygen species generated during the catalytic process was hydroxyl radicals. More importantly, a colorimetric method for glutathione detection was developed based on the peroxidase-like activity of the PCN-224-PDA-Pt. The linear detection range was 1–600 μM and the detection limit reached 0.306 μM. This method shows good anti-interference capabilities and excellent recovery rates, indicating its strong potential for applications in biological detection.