A Miniaturized Flow Injection Analysis System for Electrogenerated Chemiluminescence−Based Assays

Abstract

A new miniaturized flow injection analysis (FIA) system for developing electrochemiluminescence (ECL)-based assays is presented. Novel thin-layer flow−cell (TLFCL) screen-printed carbon electrodes integrated in one-channel flow cells were used as the electrode surface. These TLFCL electrodes, combined with miniaturized electrochemical and optical instrumentation, allowed a high degree of automation and simplicity of the assay. The performance of this high-throughput flow system was corroborated with a proof-of-concept centered on H2O2 detection. For that purpose, an ECL transduction chemistry mechanism based on a electrochemiluminescence resonance energy transfer (ECL-RET) donor−acceptor strategy, between an electro-oxidized luminophore (luminol) to a fluorophore (fluorescein), in the presence of the analyte of interest, was carried out. The results showed that fluorescein ECL-RET luminescent response increases the sensitivity of H2O2 detection by up to one order of magnitude, in comparison with a luminol−H2O2 fluorescein-free assay. All experiments were performed in a decentralized, small-sized, easy-to-use FIA system coupled to ECL detection instrumentation.