Electrochemical Sensor of Human Serum Albumin Bio-analyte Prepared Utilizing a Thin Film of Polydopamine/TiO₂ Nanoparticles: Experimental and Docking Theoretical Investigations

A new sensitive and selective sensor was developed for the detection of human serum albumin (HSA), in which the key factor was the expanding surface active sites and boosting the electro-conductivity of the carbon paste electrode (CPE) utilizing a thin film of polydopamine (PDA)/TiO₂ nanoparticles (NPs). Here, PDA was modified as an environmentally friendly polymer on the surface of TiO₂ NPs, which provided selective interaction platform toward HSA. The properties of the used TiO₂ NPs were evaluated using FE-SEM, XRD, and EDS techniques. Next, the selective interaction of PDA with HSA was studied using cyclic voltammetry and differential pulse voltammetry techniques. Molecular docking was also used to model the interaction of DA with HSA to verify the results obtained using experimental methods. This proposed strategy enables sensitive and selective detection of HSA over a dynamic range of 37–555 μM with a lower limit of detection of 10.3 μM.