A wide variety of electroanalytical techniques, including Scanning Electrochemical Microscopy (SECM), have been used for studying different cell systems. In this presentation, recent developments in the applications of SECM to study cancer cells and microbial biofilms will be reported.  Further, efforts to use a novel electrochemical nitric oxide generation method to prevent biofilm formation on polymer surfaces will be described.With respect to cancer cells, real time quantitative detection of thiodione (menadione-conjugate) pumped out of the HeLa cells by multidrug resistance (MDR) pumps was determined by SECM to be 140 �M when cells are exposed to 500 �M menadione. Selective blocking of these MDR pumps can be achieved (as detected by SECM monitoring of thiodione) by small molecules such as MK571 as well as by the MDR specific antibody.  SECM can also be used to study microbial biofilm of P. aeruginosa. Real time detection of pyocyanin produced by a biofilm formed from these bacteria was determined to be 2.5 �M after 6 h.  Pyocyanin (PYO) was also observed to be reduced by the biofilm, thus maintaining a reduced PYO atmosphere above the biofilm even in presence of oxygen.To prevent formation of biofilms on polymers, a novel pulsed electrochemical method to generate and modulate the release of NO, a highly potent and natural bactericidal agent, from inorganic sodium nitrite salt will also be presented. The NO is electrochemically generated by the reduction of nitrite ions by Cu(I) ions generated anodically at the surface of a copper electrode and subsequent cleaning of the rapidly passivated electrode surface by applying a cathodic voltage pulse.  This electrochemical approach is adapted to a catheter configuration and shown to dramatically reduce biofilm formation over a period of 7 days with several bacteria. Recent progress in controlling the amount of NO flux released from the catheters as well as a novel planar patch configuration via the use of specific electromodulation voltages and frequency will also be presented.

Applications of electrochemical techniques to study biological systems: From cancer cells to bacterial biofilms

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.