Direct Determination of Paracetamol in Environmental Samples Using Screen‐printed Carbon/Carbon Nanofibers Sensor – Experimental and Theoretical Studies

The paper describes the first electrochemical method (differential pulse adsorptive stripping voltammetry, DPAdSV) using a screen‐printed sensor with a carbon/carbon nanofibers working electrode (SPCE/CNFs) for the direct determination of low (real) concentrations of paracetamol (PA) in environmental water samples. By applying this sensor together with DPAdSV, two linear PA concentration ranges from 2.0×10−9 to 5.0×10−8 mol L−1 (r=0.9991) and 1.0×10−7–2.0×10−6 mol L−1 ( r=0.9994) were obtained. For the accumulation time of 90 s, the limit of detection was 5.4×10−10 mol L−1. Moreover, the SPCE/CNFs sensor and the DPADSV procedure for PA determination are potentially applicable in field analysis. The process of PA adsorption at the SPCE/CNFs surface was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and theoretical studies. In the theoretical study of the interaction of CNF and PA, the first species was modelled by graphene‐like clusters containing up to 37 rings. It was found that the preferable orientation of PA is parallel to the carbon surface with the binding energy of about −68 kJ/mol calculated by symmetry‐adapted perturbation theory (SAPT). Both the selectivity and the accuracy of the developed sensor for real sample analysis were also investigated using Polish river and sea samples.