Three-electrode analytical and preparative electrochemistry in micro-volume hanging droplets

Abstract

Abstract. Three-electrode micro-cells equipped with a conventional reference electrode (SCE) were easily constructed based on micro-volume droplets suspended by capillary forces to the fritted glass of the SCE bridge. Working and counter electrodes were simply inserted through the droplet surface, allowing classical electrochemistry to be readily performed in minute samples.

Miniaturized Electrochemical Device from Assembled Cylindrical Macroporous Gold Electrodes

“…. On the other hand, custom‐designed miniaturized three‐electrode electrochemical cells based on (ultra)microelectrodes have been developed for single‐cell measurements and analysis in limited volumes (microliter range) …”

“…[13][14][15] On the other hand, custom-designed miniaturized three-electrode electrochemical cells based on (ultra)microelectrodes have been developed for single-cell measurements [10,20] anda nalysisi nl imited volumes (microliter range). [21][22][23] Downscaling electrochemical platformsi mposes ad ecrease in the electrode footprint. As ac onsequence, this leads to deg-radationo ft he electrochemical performances (e.g.…”

A Self‐contained Two‐electrode Nanosensor for Electrochemical Analysis in Aqueous Microenvironments

“…Micro-and nanoscale electrodes have been an area of active research interest due to their ability to investigate microenvironments and provide insight into both fundamental and applied science including single-cell physiology, single-molecule and particle detection, reaction kinetics, electrical double layer effects, and high-resolution imaging [1][2][3][4][5]. Microdroplets are used to mimic small-volume environments such as those found in biological research and portable devices or in the pursuit of "green" analytical chemistry which aims to minimize the economic and ecological costs of research by reducing the amount of expensive reagents required and waste produced [6]. Prior to advancements in micro-and nanofabrication processes, droplets would be deposited on the surface of the working electrode with a reference electrode positioned within the droplet, limiting the applicability and spatial resolution of such systems [7,8].…”

“…Prior to advancements in micro-and nanofabrication processes, droplets would be deposited on the surface of the working electrode with a reference electrode positioned within the droplet, limiting the applicability and spatial resolution of such systems [7,8]. As manufacturing techniques advanced and electrode size reduced, needle-like working electrodes could be positioned within microdroplets, ranging from pico-to microliter volumes [6,9,10]. Insulated scanning tunneling microscope tips and fibers with sharp tips down to 50 nm in diameter were employed as working electrodes in small domains including individual cells [11,12].…”

Fast and complete electrochemical conversion of solutes contained in micro-volume water droplets

“…We recently established the possibility to perform electrochemical experiments within the simplest and cheapest available reaction vessel, i.e. a hanging droplet [5]. The originality of this work relied on the fact that micro-volume droplets were not "deposited" on a substrate or at the electrode surface, but left suspended at the fritted glass of a bridge compartment containing a conventional reference electrode (SCE).…”