Immobilized Ru(bpy)32+ Electrochemiluminescence Coupled with Microdialysis Sampling for On-line Studying Drug-protein Interaction

A electrochemiluminescence (ECL) sensor was developed according to the principle that Nepem-105D perfluorinated ion exchange solution can form a ion exchange membrane on the surface of platinum electrode for immobilization of Ru(bpy)32+. And thus, a novel method combining microdialysis sampling technique and ECL sensor was designed for the on-line study of the interaction between ciprofloxacin and bovine serum albumin (BSA). Under the optimized conditions, the relative ECL intensity is proportional to ciprofloxacin concentration in the range of 3.0 × 10−8−3.0 × 10−5 M with a detection limit of 1.0 × 10−8 M. The association constant of compound of ciprofloxacin and BSA and the number of the binding sites with Scatchard analysis are 3.51 × 104 M−1 and 1.49, respectively. The results indicated that this method was fast and simple for study of drug-protein interaction.