Capacitive Current Induced by dsDNA for Biosensor Applications

Abstract

The capacitive current brings important information of electrical components. It may be affected by surface modification or ion motion in a aqueous phase measured with electrodes. In this study, duplex DNA (dsDNA) was immobilized on gold electrodes and the capacitive current was measured in buffer solution with high salt concentration in a pulse stimulus. The capacitive current relaxed, which may be involved with ions and the DNA. DNA may stretch, extend, or swing under electric filed in solution. The capacitive current was recorded by difference pulse width before the DNA fully relaxed. Doxorubicin can insert to G-C base pairs in dsDNA and change the elasticity. The capacitive current was decreased with higher concentration of doxorubicin. In this study, we can detect low concentration of doxorubicin (1nM) binding with dsDNA, showing that this technique is promising for biosensor applications.