Communication—Electrochemical Single Nano-Impacts of Electroactive Shewanella Oneidensis Bacteria onto Carbon Ultramicroelectrode

Abstract

Electrochemical single nano-impacts of electroactive Shewanella oneidensis bacteria at a 7 μm diameter carbon fibre ultramicroelectrode in an aqueous potassium phosphate buffer (pH = 7.2) solution containing a redox active probe (potassium ferro-or ferricyanide) is reported. We present chronoamperometric measurements recorded at the ultramicroelectrode polarized at the potential of the steady-state current of the redox probe in solution (oxidation for K 4 Fe(CN) 6 or reduction for K 3 Fe(CN) 6 ) in the presence of bacteria. The shape of current transients associated to single bacteria nano-impacts is compared and discussed as a function of the redox probe in solution and of the ultramicroelectrode applied potential.

Recent advances in single liposome electrochemistry

“…Although the blocking method is an efficient single collision technique for determining the frequency and the height of the current steps during the particle adsorption onto the UME surface [4,14,42,44,45], the reactor method brings more information on the mechanism of the electroporation process and the liposome content release [4,9,15,33,46]. The liposomes size distribution calculated from the charge passed in each current spike (by peak integration) in the i-t curve is a crucial information on the electrolysis process occurring upon impact onto the UME surface.…”

Influence of Electroosmotic Flow on Stochastic Collisions at Ultramicroelectrodes

“…Lactococcus lactis was chosen here as a model bioanalyte to probe transport of analyte particles in blocking collision experiments. Interest in electrochemical collisions of bacterial analytes has been increasing, ,, especially for electroactive bacteria. , This manuscript first presents representative i – t data for blocking collisions of L. lactis.…”

“…Interest in electrochemical collisions of bacterial analytes has been increasing, 12,25,26 especially for electroactive bacteria. 27,28 This manuscript first presents representative i−t data for blocking collisions of L. lactis. We then describe a finite element model of the experiment domain developed to include convection due to electroosmotic flow.…”

Three-Mediator Enhanced Collisions on an Ultramicroelectrode for Selective Identification of Single Saccharomyces cerevisiae

“…Therefore, pursuing novel analytical methods for ultrasensitive and specific detection of target microbes is critical not only for pathogen control but also for the safe use of S. cerevisiae in industrial scale biotechnology applications. , The electrochemical collision technique provides a useful tool in the sensitive detection and statistical analysis of single entities, which has been applied in the detection of single particles, − vesicles, − viruses, bacteria, − and so forth. Even though the sensitive detection of a single analyte has been achieved by differentiating the current transients one at a time, the great challenge of electrochemical collision technique lies in the selective and specific detection of the target analytes.…”