Novel poly(diaquabis(1,10-phenanthroline)copper(II)chloride) modified glassy carbon electrode for square wave voltammetric determination of aspirin in tablet samples

In this study, potentiodynamically fabricated poly (diaquabis(1,10-phenanthroline) copper(II)chloride) modified glassy carbon electrode (poly(A₂P₂CuC)/GCE) is reported for detection of aspirin in tablet samples. EIS and CV analysis of Fe(CN)₆]^3-/4- at the modified electrode revealed surface modification by an electroactive polymer material that improved electrode effective surface area and charge transfer resistance. An oxidative peak without a reductive peak in the reverse scan direction for aspirin at poly(A₂P₂CuC/GCE augmented by peak potential shift with scan rate showed the irreversibility of the electrochemical oxidation of ASA at the electrode. A better R² (0.9983) for dependence of peak current on square root of scan rate than R² (0.9612) on scan rate indicated that oxidation of aspirin at poly(A₂P₂CuC)/GCE was predominantly diffusion mass transport controlled. Under optimized PBS pH (5.5), and square wave parameters, oxidative peak current response of poly(A₂P₂CuC)/GCE showed linear dependence on the concentration of aspirin in the range 1–200 ​μM with associated %RSD under 3.7% (n ​= ​3), limit of detection 0.039 ​μM, and limit of quantification and 0.13 ​μM. Spike recovery result in the range 96.5–100.5% with %RSD under 1.9% (n ​= ​3), and interference recovery in the range 97.2–103.4% in the presence of 50–200% of uric acid, ascorbic acid, and glucose as potential interferents validated the applicability of the developed method for determination of aspirin content in tablet samples. Detection of aspirin in the studied tablet samples in an amount 99.4–101.5% of their nominal values with %RSD under 2.6% using the present method showed the applicability of the method to control the aspirin content in tablet samples. The present method showed better performance over the previously reported methods for determination of aspirin in tablet samples making it an excellent candidate.