Innovative use of shrimp shell powder in carbon paste electrode for the electrochemical detection of dopamine and paracetamol: Valorization, characterization and application

The present study outlines the design of an innovative, cost-effective, and environmentally friendly electrochemical sensor, based on a carbon paste electrode (CPE) modified by shrimp shell waste (SSW). The developed electrode was used to facilitate the electrocatalytic detection of two compounds, namely dopamine (DA) and paracetamol (PAR). The use of SSW as an electrode material is ground breaking. The results have shown that the addition of shrimp shell (SS) in the CPE has led to a significant increase in the active surface area (0.504 cm2) and has improved electron transfer by decreasing the charge transfer resistance (17.45 Ω.cm2) at the electrode/solution interface. The SSW was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and fourier transform infra-red (FTIR). The results show a fibrous and porous structure with high calcium content and other chemical elements including carbon, oxygen, sulphur, phosphorus and nitrogen. The electrochemical behavior of DA and PAR on the CPE-SS electrode was studied using cyclic voltammetry (CV), chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) techniques. Additionally, CPE and CPE-SS electrodes were examined by SEM/EDS and FTIR. The effect of scan rate shows that the electrochemical process is diffusion controlled for DA and PAR. The CPE-SS electrode provide a wide linear range, good selectivity, repeatability, precision (≤5%), and low detection limits 3.6 µM and 5.54 µM for DA and PAR, respectively. In addition, the developed sensor was applied to detect DA and PAR in urine, tap water, and pharmaceutical tablets with apparent recoveries.