Highly conductive boron-doped diamond (BDD) electrodes are well suited for performing electrochemical measurements of nucleic acids in aqueous solution under diffusion-only control. The advantageous properties of this electrodic material in this context include reproducibility and the small background currents observed at very positive potentials, along with its robustness under extreme conditions so offering promising capabilities in future applications involving thermal heating or ultrasonic treatment. tRNA, single and double stranded DNA and 2'-deoxyguanosine 5'-monophosphate (dGMP) have been studied and well defined peaks were observed in all cases, directly assignable to the electro-oxidation of deoxyguanosine monophosphate.

A new electrically heated carbon paste electrode has been developed for performing adsorptive stripping measurements of trace nucleic acids. Such coupling of electrochemistry at electrically heated electrodes with adsorptive constant-current stripping chronopotentiometry offers distinct advantages for trace measurements of nucleic acids. The application of increased temperatures during the deposition step results in dramatic (4-34-fold, depending on temperature applied) enhancement of the stripping signal. Such improvement is attributed to the accumulation step at the heated electrode. Forced thermal convection near the electrode surface facilitates the use of quiescent solutions and hence of ultrasmall volumes. Using an electrode temperature of 32 degrees C and a quiescent solution during the 1-min accumulation, the response is linear over the 1-8 mg/L range tested, with a detection limit of 0.5 mg/L. Such electrode heating technology offers great promise for various applications involving thermal manipulations of nucleic acids.

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