Poly(para toluene sulphonic acid) and gold nanoparticles modified glassy carbon electrode for simultaneous voltammetric sensing of xanthine and hypoxanthine.

ABSTRACT

A voltammetric sensor has been developed for the individual as well as simultaneous determination of xanthine (XA) and hypoxanthine (HX) based on an electroactive-polymerised layer of para toluene sulphonic acid and gold nanoparticles composite modified glassy carbon electrode ([p(PTSA)]/AuNPs/GCE)]. Under optimized conditions, an enhancement in the oxidation currents with well-separated and well-resolved peak position and a lower shift in the peak potentials were observed. By square wave voltammetry, the simultaneous determinations of XA and HX were achieved in the linear ranges 6.00 × 10-4 M to 3.00 × 10-6 M and 5.00 × 10-4 M to 1.00 × 10-5 M with detection limits of 4.09 × 10-7 M and 4.10 × 10-7 M, respectively. The mechanistic aspects were unveiled from linear sweep voltammetric studies and found that the electrode processes were diffusion-controlled. Finally, the sensor was successfully employed for the simultaneous determination of spiked amount of XA and HX in synthetic urine and serum samples.