A novel ratiometric electrochemical sensing strategy for monitoring of peroxynitrite anion released from high glucose-induced cells

Monitoring of reactive nitrogen species (RNS) released from cells under high glucose induction is of great importance due to their significant contributions in the occurrence and development of diabetes mellitus (DM). Here, we developed a novel ratiometric electrochemical sensor based on platinum/hollow tubular conjugated organic microporous polymer/chitosan (Pt/HTCMP/CTS) and used for the detection of peroxynitrite anion (ONOO − ), which is the main member of RNS. A "signal on-off" ratiometric dual-signal strategy was designed by using of the redox characteristics of K 3 [Fe(CN) 6 ] ([Fe(CN) 6 ] 4- ) and the analyte (ONOO − ) for the first time. Then, due to the significant enhancement for the ratio of oxidation current value (I ONOO − /I [Fe(CN)6]4- ), the sensor showed excellent analytical performance over a wide range from 3.09 × 10 -10 to 1.20 × 10 -4 M and a detection limit as low as 0.103 nM (S/N = 3). Importantly, in high glucose environment, ONOO − and H 2 O 2 released from cancer cells were monitored directly with the proposed sensor for the first time. Therefore, the study provides an effective method for realizing fast, reliable and ultra-sensitive determination of ONOO-, and exhibits significant application value in biomedical analysis and clinical diagnosis.