Electrodeposition of gold-platinum nanoparticles on 2D M-TCPP (M = Co, Cu, Zn) for electrochemical monitoring of H2O2 from living cells

Two-dimensional (2D) metal–organic frameworks (MOFs) as supporting nanomaterials to encapsulate or load metal nanoparticles have been widely applied in electrochemical sensing. Therefore, the influences of tetrakis(4-carboxyphenyl) porphyrin-based MOFs (M-TCPP (M = Co, Cu, Zn)) as supporting materials on the electrocatalytic activity were studied. A surfactant-assisted method was employed to facilely synthesize three types of 2D M-TCPP nanosheet MOFs. Polyvinylpyrrolidone was selected as a surfactant for preparing M-TCPP and played a key role in the controlled anisotropic growth of MOF crystals, resulting in the formation of 2D MOF nanosheets. Then, one-step electrodeposition of gold-platinum nanoparticles (AuPt NPs) on the M-TCPP-modified glassy carbon electrode (AuPt/M-TCPP/GCE) was explored for reducing hydrogen peroxide (H2O2). Cyclic voltammetry was applied to investigate the electrocatalytic performance of AuPt/M-TCPP/GCE, and AuPt/Cu-TCPP/GCE exhibited better electrocatalytic characteristics than AuPt/Co-TCPP/GCE and AuPt/Zn-TCPP/GCE. The electrochemical H2O2 sensor displayed a low detection limit of 3.1 nM in the wide concentration range of 0.01 μM to 80 mM. In addition, the proposed sensor showed high stability, good reproducibility, and selectivity. Moreover, HepG2 human liver cancer cells were selected for real-time detection of H2O2 to verify the feasibility of this technology for the evaluation of anticancer drugs. The results showed that Cu-TCPP can be used as an efficient supporting material for enhancing the detection property of electrochemical sensors.