Designing a novel, ultra-sensitive, and biocompatible electrochemical nano-biosensor for the detection of tryptophan and bovine serum albumin using zirconium dioxide nanostructures

In the dynamic field of electrochemical biosensors, the demand for facile yet highly sensitive electrode materials is paramount. This study presents an innovative electrochemical biosensor material designed for the detection of biologically crucial molecules-Tryptophan (Trp) and Bovine serum albumin (BSA) utilizing ZrO2 nanoparticles (NPs). Through a successful hydrothermal synthesis, nanosized ZrO2 was employed to modify a glassy carbon electrode (GCE), constituting a novel electrochemical biosensor material. Characterization techniques, including XRD, FE-SEM, EDS, and FT-IR, elucidated the monoclinic crystalline structure, cauliflower-like surface morphology, elemental composition, and chemical state of the prepared NPs. Optical properties were explored using UV-Visible and photoluminescence spectroscopic methods. The electrochemical sensing ability of ZrO2 NPs modified GCE were evaluated through cyclic voltammetry (CV) techniques with meticulous optimization of measurement parameters, revealing a modified GCE shows superior electrocatlytic property towards detection of Trp and BSA molecules as compared to bare GCE due to the large specific surface area of the ZrO2 NPs. The ZrO2 NPs modified GCE exhibited exceptional electrochemical signals, showcasing a linear response within concentration ranges of 1-16 μM for Trp and 1.50-42 nM for BSA. Impressively low detection limits of 0.49 μM and 0.90 nM for Trp and BSA, respectively, were achieved. The electro-oxidation mechanism of Trp were investigated by varying the scan rates and the relation between peak and scan rate revealed that, oxidation process of Trp at ZrO2 NPs modified GCE is an adsorption-controlled process. Further, the effect interference substance on detection of Trp and BSA were conducted by linear sweep volatmmetry measurements in the absence and presence of interfering compounds, and results endorse that, ZrO2 modified GCE has good selectivity in detection of Trp and BSA. This novel electrochemical sensor demonstrated significant sensitivity, selectivity and a low detection limit, underscoring the potential for ZrO2 NPs in advancing the development of biosensor devices.