Enzymeless detection and real-time analysis of intracellular hydrogen peroxide released from cancer cells using gold...

Abnormal cell growth and proliferation can lead to tumor formation and cancer, one of the most fatal diseases worldwide. Hydrogen peroxide (H₂O₂) has emerged as a cancer biomarker, with its concentration being crucial for distinguishing cancer cells from normal cells. Herein, a cost-effective and enzymeless electrochemical sensing system for the monitoring of intracellular H₂O₂ has been constructed. The sensor is fabricated using gold nanoparticles embedded bimetallic copper/nickel metal organic framework (Au-CNMOF) immobilized reduced graphene oxide (RGO) modified screen printed electrode (SPE). The synthesized materials were characterized and confirmed by XRD, FTIR, SEM with EDS, and electrochemical analysis. The fabricated sensor displayed a redox peak at a formal potential (E°) of -0.155 V, corresponding to Cu^II/I redox couple of CNMOF in 0.1 M phosphate buffer. Electrochemical investigations revealed that the proposed sensor has a large electrochemical active surface area (1.113 cm²) and a higher surface roughness (5.67). Additionally, the sensor demonstrated excellent electrocatalytic activity towards H₂O₂ at -0.3 V, over a wide linear detection range from 28.5 µM to 4.564 mM with a limit of detection of 4.2 µM (S/N=3). Furthermore, the proposed sensor exhibits excellent stability, repeatability, reproducibility, and good anti-interference activity. Ultimately, the sensor was validated through real-time analysis of H₂O₂ released from cancer cells, successfully quantifying the released H₂O₂. The developed sensor holds great promise for real-time H₂O₂ analysis, with potential applications in clinical diagnostics, biological research and environmental monitoring.