Cisplatin-based DNA sensing with enhanced current response.

A novel electrochemical technique for DNA detection has been developed by a simple combination cisplatin and a glassy carbon electrode. The complexation of cisplatin with DNA caused suppression of the electroreduction of cisplatin owing to the steric hindrance and, subsequently, the electrolytic current for reducing proton that is catalyzed by the platinum deposited on the glassy carbon electrode by the electroreduction of cisplatin. Thus the DNA content was determined from the decrease in the catalytic activity of the electrode: an enhanced current response for measuring the current for reducing proton as compared with that for reducing cisplatin itself could provide the highly-sensitive measurement of cisplatin. The detection limit for herring DNA was as low as 0.1 ng/mL.