Analytical Sciences

Abstract − Analytical Sciences, 27(1), 67 (2011).

Electrochemical Sensing of Acyclovir at a Gold Electrode Modified with 2-Mercaptobenzothiazole–[5,10,15,20-tetrakis-(3-methoxy-4-hydroxyphenyl)porphyrinato]copper(II)
Renjini JOSEPH and K. Girish KUMAR
Department of Applied Chemistry, Cochin University of Science and Technology, Kochi-682 022, India
The electrooxidation of acyclovir (ACV) was studied using a gold electrode (GE) modified with a self-assembled monolayer of 2-mercaptobenzothiazol (MBZ) and [5,10,15,20-tetrakis(3-methoxy-4-hydroxyphenyl)porphyrinato]copper(II) (TMHPP Cu(II)) by square wave voltammetry (SWV). The self-assembled films are stable and showed blocking characteristics towards the faradaic processes such as gold surface oxidation and under potential deposition of copper. The optimized conditions obtained for the MBZ/TMHPP Cu(II)-modified GE were 0.1 M phosphate buffer solution (pH 7.0), square wave frequency of 15 Hz and square wave amplitude of 25 mV. Under these optimum conditions, the resultant peak current increases linearly with the concentration of ACV in the range of 1.0 × 10−3 to 1.0 × 10−8 M with a detection limit of 1.0 × 10−8 M. The MBZ/TMHPP Cu(II)-modified GE showed good stability and selectivity and it can be used to quantify ACV in pharmaceutical formulations and urine samples.