Synthesis, characterization, and electrochemical application of novel poly(Cu2P4BCl4) based glassy carbon electrodes for determination of sulfamethoxazole in pharmaceutical serum and urine samples and Cow’s milk

Abstract

The synthesis of the novel complex, [Cu2P4B]Cl4·H2O (in short Cu2P4BCL4), was confirmed by UV–Vis and FT-IR data after a straightforward ion exchange reaction. The electrochemical fabrication of the Nobel Cu2P4BCl4-based GCE was done potentiodynamically by scanning the potential of the glassy carbon electrode on the buffer solution containing 1.0 mM Cu2P4BCl4. EIS and CV were employed to characterize the surface of the developed sensor. The electroactive area and charge transfer capacity of the modified electrode were improved by about 2.5-fold area and 100-fold double-layer capacitor, respectively. The electrochemical activity of the Sulfamethoxazole (SMX) on the developed electrode was improved at around 3.1-fold peak intensities. The poly(Cu2P4BCl4)/GCE showed a wide linear range of the concentration of SMX from 0.1 to 200 µM at pH 6.5. The LOD and LOQ of the developed sensor were 0.112 nM and 0.375 nM, respectively, with the associated %RSD of 0.26 % (for n = 7). The validation of the real application of the fabricated electrode for the determination of SMX was investigated by detecting the cow’s milk sample, serum, and urine samples with spike recovery in the range of 97.5–103 %. The selectivity of the developed sensor towards SMX in the presence of potential interferants revealed an excellent recovery percentage in the range of 98.66–102.7 % in the presence of 50 to 200 % of potential interferents indicating an excellent accuracy and selectivity of the sensor. The stability and reproducibility of the Nobel sensor were investigated and revealed the best means for electrochemical determination of SMX from real cow’s milk, serum, and urine samples.