One-step modification of various electrode surfaces using diazonium salt compounds and the application of this technology to electrochemical DNA (E-DNA) sensors

In this work, we have demonstrated that 4-carboxy phenyl groups based modification could be performed on different electrodes, such as indium tin oxide (ITO), gold (Au), and glassy carbon electrode (GCE). The electrode modification has been performed through cyclic voltammetry by sweeping the potential between +1.0 V and −1.0 V for ‘n’ number of potential cycles. The 4-carboxyphenyl modification at different electrode surfaces was confirmed by cyclic voltammetry, contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy analysis. Subsequently, the electrochemical DNA sensor (E-DNA sensor) based on the 4-carboxy phenyl modified GCE was fabricated by the immobilization of probe DNA. The fabricated E-DNA sensor can detect the influenza virus (type A). The current density of the E-DNA sensor was also evaluated by cyclicvoltammetry when the probe DNA and target DNA were hybridized.