Sensitivity of electrochemically nanostructured carbon fiber ultramicroelectrodes in the determination of adenosine

A direct and fast voltammetric method of determination of adenosine, with a novel carbon fiber ultramicroelectrode (CFE), is demonstrated here. To ach ieve high sensitivity required in biological determinations, before the det ermination of adenosine, carbon fiber ultramicroelectrodes were activated b y electrochemical pretreatment. The electrochemical activation process gene rates a nanostructured carbon fiber surface which is stable. The high stabi lity of the active surface, and the high reproducibility of the activation process, leads to reproducible and sensitive fast scan voltammetric (FSV) d eterminations of adenosine. Adenosine sensitivity was determined in 7 x 10( -2) M phosphate buffer, pH 7.4, at a scan rate of 500 V s(-1). The potentia l window in the determinations was from -1.0 to 1.5 V (vs. SCE). A high sen sitivity of the new method of adenosine determinations was achieved under p hysiological conditions.