A novel electrochemical sensor based on microporous polymeric nanospheres for measuring peroxynitrite anion released by living cells and studying the synergistic effect of antioxidants
Peroxynitrite anion (ONOO–) is a crucial reactive nitrogen species (RNS), which has aroused immense research interest in the biological and biomedical fields because aberrant expression levels of ONOO– are related with many diseases. In this work, a novel electrochemical sensor is described for detection of peroxynitrite anion (ONOO–) released from living cells. It is constructed by a glassy carbon electrode (GCE) decorated with nanocomposites (CTS-MPNS) synthesized from chitosan (CTS) functionalized microporous polymeric nanospheres (MPNS). The prepared CTS-MPNS/GCE sensor shows a supernormal manifestation in measuring ONOO– in a wide range of concentrations from 3.83 nM to 0.104 mM and the detection limit is as low as 1.28 nM (S/N = 3), which makes it possible to detect traced amounts of ONOO– released from U87 cells. Signiﬁcantly, the synergistic effect of different antioxidants to scavenge ONOO– in the biological systems is further studied by electrochemical method for the first time, which provides an efficient strategy protecting the cells against oxidative stress. In the authors’ perception, the developed platform and the efficient strategy may pave the way for their future applications in the field of biomedicine and treatment of cancer diseases.