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

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 H 2 O 2 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 H 2 O 2 detection by up to one order of magnitude, in comparison with a luminol−H 2 O 2 fluorescein‐free assay. All experiments were performed in a decentralized, small‐sized, easy‐to‐use FIA system coupled to ECL detection instrumentation.