Tosyl-carbon nanoparticles modified glassy carbon electrode: Application for determination of Adenine

Adenine (Ade) is an important component of deoxyribonucleic acid (DNA) and is involved in the key function of carrying genetic instructions Therefore, sensitive determination of Ade indicates relevance in clinical diagnosis [1]. Different methods including HPLC [2], capillary electrophoresis [3] and electrophoresis combined [4] have been introduced for the determination of Ade. Compared with these methods, electrochemical techniques are widely used for determination of electroactive analyts due to its sensitivity, rapidity, simplicity, and low-cost.In this work a simple and fast procedure was developed to prepare an electrochemical sensor based on a glassy carbon electrode (GCE) modified with thin film of tosyl surface carbon nanoparticles (tosyl-CNP). The modifier was characterized by field emission scanning electron microscopy, fourier transform infrared spectroscopy, and the modified electrode was investigated by cyclic voltammetry and differential pulse voltammetry. The modified glassy carbon electrode shows high electrocatalytic activity toward the oxidation of Ade and therefore the obtained sensor was applied to the determination of Ade. Linear relationships between peak current in differential pulse voltammetry and Ade concentrations were obtained in the range from 0.5 μM to 20 μM with detection limits of 0.25 μM. Furthermore, the sensor shows high sensitivity, good selectivity, good reproducibility, and long-term stability to Ade determination.