Under optimal conditions, a graphene film modified glassy carbon electrode exhibited a longer linearity range from 3.36 to 57.12 ng mL−1 of acebutolol with a limit of detection of 0.131 ng mL−1.

The electrochemical behavior of aspirin at a graphene modified glassy carbon electrode has been investigated using cyclic and differential pulse voltammetric techniques. The dependence of the current on pH, concentration and scan rate was investigated to optimize the experimental conditions for determination of aspirin. A plausible oxidation mechanism was proposed. Under the optimum conditions, the oxidation peak current was linearly proportional to the concentration of aspirin in the range from 1.00×10−6 to 2.00×10−4 M with a detection limit of 20.2 nM. The proposed method was successfully applied to aspirin determination in pharmaceutical and real samples.

A simple, rapid, selective, and sensitive electrochemical method for the direct determination of indomethacin was developed. The electrochemical behavior of indomethacin was carried at multiwalled carbon nanotube-(MWCNTs-) modified glassy carbon electrode (GCE). The cyclic voltammetric results indicated that MWCNT-modified glassy carbon electrode remarkably enhanced electrocatalytic activity towards the oxidation of indomethacin in slightly acidic solutions. It led to a considerable improvement of the anodic peak current for indomethacin and could effectively accumulate at this electrode and produce two anodic peaks at 0.720 V and 0.991 V, respectively, and one reduction peak at 0.183 V. The electrocatalytic behavior was further exploited as a sensitive detection scheme for the determination of indomethacin by differential-pulse voltammetry (DPV). Under optimized conditions, the concentration range and detection limit were 0.2 to 6.0 M and 13.2 nM, respectively. The proposed method was successfully applied to determination of Indomethacine in pharmaceutical samples. The analytical performance of this sensor has been evaluated for detection of analyte in human serum and urine as real samples.