Cu₃N–Fe nanocube-based electrochemical sensing of cancer metabolites with minute-scale response time

This work describes an electrochemical biosensor using iron-doped copper nitride (Cu₃N–Fe) nanostructures for the rapid detection of hydrogen peroxide (H₂O₂), a key metabolic biomarker released by cancer cells. The sensor, prepared by drop-casting the nanocomposite onto a glassy carbon electrode, shows high electrocatalytic activity towards H₂O₂ oxidation, with a wide linear range from 0.01 mM to 1 M and a detection limit of 9.8 µM. The sensor successfully differentiated multiple cancer cell lines from non-cancerous controls and was clinically validated using 28 cancer patient tissue samples, distinguishing cancerous from adjacent normal tissues with approximately 90% accuracy. A strong positive correlation was established between the response of the sensor and the expression levels of formyl peptide receptor-1 in the cancer tissues, which validates the sensing mechanism. This work shows the potential of Cu₃N-Fe as a material for developing cost-effective, point-of-care diagnostic tools for rapid, qualitative cancer screening.