Mapping the reactivity of a redox-sensitive luminescent microobject positioned in fluxes of reactive species allows analyzing complex mechanistic processes such as the electrogenerated chemiluminescence of model systems used in immunoassays.

Abstract:We have investigated the electrochemical oxidation of a number natural phenolics (salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, protocatechuic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, quercetin and rutin) using cyclic voltammetry. The antioxidant properties of these compounds were also studied. A structural analysis of the tested phenolics suggests that multiple OH substitution and conjugation are important determinants of the free radical scavenging activity and electrochemical behavior. Compounds with low oxidation potentials (Epa lower than 0.45) showed antioxidant activity, whereas compounds with high Epa values (>0.45) act as prooxidants.

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Swimmer in the dark: propulsion of a conducting object is intrinsically coupled with light emission using bipolar electrochemistry. Asymmetric redox activity on the surface of the swimmer (black bead) causes production of gas bubbles to propel the swimmer in a glass tube with simultaneous electrochemiluminescence (ECL) emission to monitor the progress of the swimmer.