Fabrication of an effective peroxynitrite electrochemical sensing platform and studying the inhibitory effect of tea polyphenols on the oxidative damage of lead-treated cells

Peroxynitrite (ONOO-), as the main reactive nitrogen species, involves many physiological and pathological conditions. Particularly, aberrant expression levels of ONOO- can cause cancer and other diseases, so its analysis have attracted the attention and concern of many scientific researchers. Here, we present a new ONOO- sensing platform to monitor cells oxidative damage directly by utilizing the conjugated organic microporous polymer/ chitosan (CMP/CS) modified glassy carbon electrode (GCE). The prepared CMP/CS/GCE shows excellent electrochemical performance for measuring ONOO- in the wide concentration range of 2.29 nM to 45.8 mu M and the detection limit is as low as 0.763 nM (S/N = 3). Therefore, we used this sensor for the detection of ONOO- released from glioma cells (U87) during oxidative stress induced by lead stimulation. Significantly, the inhibitory effect of tea polyphenols (TP) on the oxidative damage of lead-treated cells was explored by electrochemical method for the first time, and the maximum non-toxic concentration range of TP was obtained. In the authors' perception, the constructed sensing platform and the efficient analysis method may open a new path for their future use in living organisms.