ABSTRACT This review documents the re-emerged interest in traditional electroanalysis, amperometry at mercury drop electrodes, inspired by the discovery of stochastic adhesion signals of single soft particles at the dropping mercury electrode (DME), which preceded the development of single entity electrochemistry (SEE). The random occurrence of adhesion events is due to the spatial heterogeneity inherent to a dispersed system and to the stochastic nature of the particles’ encounter with the electrode. The amperometric adhesion signals of individual microparticles contain unique information on their surfaces and the interfacial interactions that can be measured directly in the aqueous environment. These intrinsic properties are important for the biological activity and self-organization. The review covers studies in model dispersions of hydrocarbon droplets allowing the thermodynamics and dynamics of adhesion at the three-phase boundary to be defined. The new approach was extended to studies of adhesion signals from suspensions of living cells of marine algae to measure their surface charge density, organization and interfacial forces involved in adhesion. The extensive experimental research and modelling of single liposome adhesion signals, that followed, included some contradicting interpretations of the mechanism and kinetics of adhesion. Further research is clearly needed to critically evaluate interpretations of the stochastic adhesion signals at the molecular level. The combination of fast and direct particle characterization through their adhesion signals with high resolution imaging by atomic force microscopy (AFM) sets the observation window below the micrometer scale that allows direct characterization of submicron particle dynamics in marine environments by decoupling biotic production from abiotic self-assembly processes of biopolymers in their formation.
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