An Efficient Electrochemiluminescence Enhancement Strategy on Bipolar Electrode for Bioanalysis

This paper develops an efficient electrochemiluminescence (ECL) enhancement strategy on closed bipolar electrode for the detection of prostate specific antigen (PSA). We first synthesized a cyclometalated iridium­(III) complex (pq)₂Irbza with high ECL efficiency and used as ECL emitter in the anodic cell of BPE. While we introduced a Pt-tipped Au NRs and constructed a sandwich immune structure at the cathodic pole of BPE. Combined the signal amplification strategies of enzyme catalysis and the synergistic catalytic effect of bimetallic structure for the reduction of H₂O₂, the attached Pt-tipped Au NRs-GOx-Ab₂ nanocomplex as both recognition probes and signal amplification units could mediate the ECL signals of (pq)₂Irbza/tripropylamine (TPrA) on the anodes of BPE through faradaic reaction due to the charge neutrality of BPE. Therefore, a highly sensitive BPE-ECL sensor for detection of PSA with a detection limit of 0.72 pg/mL and a linear range from 1.0 pg/mL to 10 ng/mL was obtained. This work is expected to broaden the application of iridium complex and bimetallic nanocatalyst in biological detection and could be utilized to detect many other biological molecules.