Stripping Analysis of Nucleic Acids at a Heated Carbon Paste Electrode

• Published in: Analytical chemistry (Washington) 2000-08, Vol.72 (16), p.3752-3756
• Main Authors: Wang, Joseph, Gründler, Peter, Flechsig, Gerd-Uwe, Jasinski, Markus, Rivas, Gustavo, Sahlin, Eskil, Lopez Paz, Jose Luis
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Carbon; Electrodes; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; Hot Temperature; Nucleic acids; Nucleic Acids - analysis; Organic chemistry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac000286q

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 °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.