Electrochemical oxidation of acetyl salicylic acid and its voltammetric sensing in real samples at a sensitive edge plane pyrolytic graphite electrode modified with graphene.

We present in this manuscript for the first time the electrochemical oxidation of acetyl salicylic acid and its voltammetric sensing in real samples at a sensitive edge plane pyrolitic graphite electrode (EPPGE) modified with graphene. The electrochemical response of the sensor was improved compared to edge plane pyrolytic graphite electrode and displayed an excellent analytical performance for the detection of acetyl salicylic acid .These characteristics were attributed to the high acetyl salicylic acid loading capacity on the electrode surface and the outstanding electric conductivity of graphene. A linear response was obtained over a range of acetyl salicylic acid concentrations from 10 nM to 100nM into a pH 4 buffer solution (N defined as the sample size N = 7) with a detection limit of 3 nM based on (3-s/slope). The methodology is shown to be useful for quantifying low levels of acetyl salicylic acid in a buffer solution. The protocol is also shown to be applicable for the sensing of acetyl salicylic acid in human oral fluid samples. A linear response was obtained from 30nM to 150 nM into a human oral fluid solution (N = 7) with a detection limit of 17.3nM. Cyclic Voltammetry (CV) using EPPG modify with graphene has been employed in the proposed method for the determination of ASA in drug preparations and human oral fluid