ABSTRACT
The application of a RuDen-doped CCE to the determination of biochemical compounds was investigated by flow-injection amperometry with methionine and with cystine as analytes. Hydrodynamic voltammogram showed that at 1.10 V versus Ag/AgCl, current responses to methionine at pH 7.0 and to cystine at pH 2.3 (0.10 M phosphate buffer) carrier were achieved (Table 1). The catalysis of the oxidation of the disulfide, cystine, suggested that the oxidation of insulin will be promoted by RuDen. Cyclic voltammetry at a glassy carbon electrode of a solution containing 40 µM RuDen and 150 µM insulin (in 88% [vol.] pH 11 buffer and 12% CH3CN) showed the mediated oxidation of insulin [40]. Extending the study to CCEs and to measurement at physiological pH is the next step in the test of the utility of RuDen.
