Microelectrochemical visualization of oxygen consumption of single living cells.

The detection of cellular respiration activity is important for the assessment of the status of a biological cell. Due to its non-invasive character and high spatial resolution scanning electrochemical microscopy (SECM) is a powerful tool for single cell measurements. Common limitations of respiration studies performed by SECM are discussed and strategies provided to further adapt SECM detection schemes to the specific requirements for the investigation of single cell respiration. In particular the combination of a potential pulse technique in the redox competition mode of SECM with a shearforce-based constant-distance positioning of the SECM tip is proposed for characterising the impact of the tip reaction during SECM imaging. The adjustment of the driving force of the tip reaction and the selection of the time for data acquisition after applying the potential pulse allowed a successful visualization of cell respiration activity.