Electrochemiluminescence behavior of 2-Hydroxynicotinic acid and identification of phloxine B by electrochemiluminescence resonance energy transfer

In this work, we first reported the electrochemiluminescence (ECL) properties of 2-hydroxynicotinic acid (2-HNA) with 0.09 M K 2 S 2 O 8 in 0.5 M H 3 BO 3 – Na 2 B 4 O 7 buffer solution. The effects of the type of co-reactant, the concentration of K 2 S 2 O 8 and the pH of the buffer solution on the ECL intensity of this system were investigated. And the possible mechanism of 2-HNA/ K 2 S 2 O 8 system has been speculated by fluorescence spectrum and ECL spectrum. Besides, we found that phloxine B (PB) can significantly enhance the ECL intensity of the 2-HNA/ K 2 S 2 O 8 system. It is speculated that an electrochemiluminescence resonance energy transfer (ECL-RET) process may occur between 2-HNA and PB, so that PB enhanced the ECL of the 2-HNA system. Combining the ultraviolet spectrum and density functional theory (DFT) calculations further proved the rationality of this speculation. Based on this, a new method of ECL detection of PB with high sensitivity and high selectivity was established.