Two-Dimensional\nTiS<sub>2</sub> Nanosheet- and Conjugated\nPolymer Nanoparticle-Based Composites for Sensing Applications

The assessment of phenolic compounds in food samples,\nenvironmental\nsamples, and medical applications has gained importance recently.\nHere, we present research on novel conjugated polymer nanoparticles\n(P-PimBzBt NPs) and their composites with two-dimensional titanium\ndisulfide nanosheets (2D-TiS<sub>2</sub>) for electrochemical tyrosinase\n(TYR)-based catechol detection. P-PimBzBt NPs are decorated with\n2D-TiS<sub>2</sub> to enhance the electrochemical performance for\nbiosensing. In addition, the interaction of P-PimBzBt NPs with TiS<sub>2</sub> was investigated at the molecular level by employing van\nder Waals (vdW) dispersion-corrected density functional theory (DFT)\ncalculations and classical all-atom molecular dynamics simulations.\nAccording to the theoretical studies, the presence of the TiS<sub>2</sub> layer increases the interfacial interaction with the conjugated\npolymer via electrostatic interactions. Using cyclic voltammetry (CV),\nelectrochemical impedance spectroscopy (EIS), field emission scanning\nelectron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy\n(EDS) analyses, the production of SPE/TiS<sub>2</sub>@P-PimBzBt NPs/TYR\nnanobiosensors was examined. With a detection range of 3.0–27.5\nμM, 0.33 μM LOD, and 3.89 μA/μM·cm<sup>2</sup> sensitivity values, the sensing layer based on the TiS<sub>2</sub>@P-PimBzBt NP composites has a targeting ability toward catechol.\nIts selectivity was investigated using commonly used interfering ions\nand compounds such as citric acid, urea, glucose, uric acid, KCl,\nand NaCl. Application of nanobiosensors to actual samples (tap water\nand black tea) was carried out with high accuracy. The fabricated\nbiosensing platform demonstrates that P-PimBzBt NPs with 2D-TiS<sub>2</sub> nanomaterial functionalization are appropriate as electrode\nmaterials and could be used to create an inexpensive, fast-response,\nand highly selective electrochemical biosensor for the detection of\ncatechol in actual samples.