Poly(3,4-ethylenedioxythiophene):Polystyrene Sulfonate-Modified Electrode for the Detection of Furosemide in Pharmaceutical Products

[Image: see text] Furosemide (4-chloro-2-(furan-2-ylmethylamino)-5-sulfamoyl benzoic acid) is a widely used, FDA-approved drug prescribed for several symptoms associated with heart, kidney, liver failure, or chronic high blood pressure. In this work, a glassy carbon working electrode modified with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate is developed to detect furosemide (FURO) with high sensitivity and precise selectivity. The modified electrode was also characterized using field emission scanning electron microscopy, attenuated total reflectance–Fourier transform infrared, and cyclic voltammetry. Here, an efficient and cost- and time-efficient technique to study the furosemide mechanism of reaction in an acidic liquid medium is presented. An electrochemical oxidation of loop diuretic furosemide was investigated in a supporting electrolyte, 0.01 M of phosphate buffer (at a pH level of 4.0) at 25 ± 0.1 °C using a differential pulse voltammetric (DPV) technique. Under optimized parameters, the developed sensor displays a wide detection range of furosemide concentrations of 6.0 × 10(–6) to 1.0 × 10(–4) M with a detection limit of 2.0 × 10(–6) M using DPV. The presented sensor offers a robust and high-precision technique with an excellent reproducibility to detect furosemide in as a real sample such as urine and pharmaceutical products.