An electrochemical sensing platform for biomonitoring the potential toxicity of plastic particles by detecting NO

•A NO electrochemical sensor based on Au/MWCNT-FeTCP/Nafion nanocomposite was constructed with specificity and low detection limit.•The sensor has excellent catalytic performance for NO released by cells and tissues induced by plastic particles.•The oxidative damage induced by plastic particles in different time and concentration was evaluated for the first time using electrochemical sensors.•An unclear cell signaling pathway about apoptosis caused by plastic particles was revealed using our sensor.•The work provided new ideas and methods for evaluating the potential toxicity of plastic particles.