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(4carboxyphenyl) 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 mu M 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.