Simultaneous Electrocatalytic Measurement of Dopamine and Acetaminophen by Nanosensor Based on Ag@Polyoxometalate@Reduced Graphene Oxide and Ionic Liquid

A novel electrochemical nanosensor was established for the simultaneous measurement of dopamine (DA) and acetaminophen (AC). The nanosensor was achieved by modification of carbon paste electrode (CPE) by Ag nanoparticle, polyoxometalate, reduced graphene oxide (Ag@POM@rGO), and ionic liquid (IL). The electrochemical behaviors of DA and AC were evaluated by Ag@POM@rGO-IL/CPE and various electrochemical methods. Design-Expert software by response surface methodology (RSM) approach was utilized to consider the interaction between the different factors. The best electrochemical response was attained with 0.01 g of IL and 0.04 g of Ag@POM@rGO in the modified electrode, phosphate buffer solution (0.1 M, pH 7.0), and a sweep rate of 0.07 V s⁻¹. In the optimum situation, the calibration curves for DA and AC were achieved in a square wave voltammetry (SWV) manner, and linear dynamic ranges (LDR) were obtained to be 0.05–115.04 µM and 0.1–137.90 µM for DA and AC, respectively. The limit of detection (LOD) was attained to be 17.0 for DA and 37.0 nM for AC. The Ag@POM@rGO-IL/CPE showed good stability, productivity and repeatability, and advanced recovery, and it has a little price and low background current. Also, the usage of this nanosensor was studied by measuring the DA and AC in the human plasma by means of worthy recovery. This technique is easy, rapid, and cheap and can be utilized as a significant device in the quantitative analysis of the medicinal product.

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