The advancement of electrode materials is essential for addressing the energy and biomedical challenges. A multi-functional approach was employed to create a new electrode material of cobalt oxide-embedded nitrogen-doped porous graphene (Co3O4@NpG) for sensing and energy storage applications. In the present study, we have fabricated a new electrochemical sensing platform based on Co₃O₄@NpG. The sensing performance and selective detection capability of the demonstrated sensor was optimized and tested by determining dopamine (DA), uric acid (UA), and ascorbic acid (AA) simultaneously in analyte fortified biological samples. The sensing response is noticed to be linearly dependent upon the concentration of AA, DA, and UA in the range of 0.1–450, 0.1–502, and 0.2–396 μM, respectively. This material also showed good electrochemical energy storage performance when assessed as a supercapacitor electrode. The Co₃O₄@NpG electrode material showcased a remarkable specific capacitance of 314.58 Fg⁻¹, an energy density of 10.06 Wh kg⁻¹ at a power density of 240 Wkg⁻¹ at 0.5 Ag⁻¹, in a 6 M KOH electrolyte, along with excellent long-term cycling stability. Hence, the material Co₃O₄@NpG stands out as a promising multifunctional electrode candidate, excelling in the precise simultaneous detection of critical biomolecules besides exhibiting superior energy storage performance.

The interaction between two proton pump inhibitors viz., omeprazole (OME) and esomeprazole (EPZ) with human serum albumin (HSA) was studied by fluorescence, absorption, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR), voltammetry, and molecular modeling approaches. The Stern–Volmer quenching constants (K_sv) for OME-HSA and EPZ-HSA systems obtained at different temperatures revealed that both OME and EPZ quenched the intensity of HSA through dynamic mode of quenching mechanism. The binding constants of OME-HSA and EPZ-HSA increased with temperature, indicating the increased stability of these systems at higher temperatures. Thermodynamic parameters viz., ∆H^°, ∆S^°, and ∆G^° were determined for both systems. These values revealed that both systems were stabilized by hydrophobic forces. The competitive displacement and molecular docking studies suggested that OME/EPZ was bound to Sudlow’s site I in subdomain IIA in HSA. The extent of energy transfer from HSA to OME/EPZ and the distance of separation in tryptophan (Trp214) Trp214-OME and Trp214-EPZ was determined based on the theory of fluorescence resonance energy transfer. UV absorption, 3D fluorescence, and CD studies indicated that the binding of OME/EPZ to HSA has induced micro environmental changes around the protein which resulted changes in its secondary structure.

Herein, we have reported on a simple, environmentally friendly, and ultra-sensitive electrode material, SnO₂@p-rGO, used in a clean sustainable manner for rapid electrochemical determination of an anti-diabetic agent, repaglinide (RPG). Three-dimensional porous reduced graphene oxide nanostructure (p-rGO) was prepared via a low-temperature solution combustion method employing glycine. The aqueous extract of agricultural waste “cotton boll peel” served as stabilizing and reducing agents for the synthesis of SnO₂ nanoparticles. The structural and morphological characterization was carried out by XRD, Raman, SEM, EDX, FTIR, absorption, and TGA. The oxidation process of RPG was realized under adsorption controlled with the involvement of two protons and electrons. The sensor displayed a wider linearity between the concentration of RPG and oxidation peak current in the ranges of 1.99 × 10⁻⁸–1.45 × 10⁻⁵ M and 4.99 × 10⁻⁸–1.83 × 10⁻⁵ M for square-wave voltammetric and differential pulse voltammetric methods, respectively. The lower limit of detection value of 0.85 × 10⁻⁹ M was realized with the SWV method. The proposed sensor was applied for the quantification of RPG in fortified urine samples and pharmaceutical formulations. Furthermore, the sensor demonstrated reproducibility, long-term stability, and selectivity in the presence of metformin and other interferents, which made the proposed sensor promising and superior for monitoring RPG.

An anticancer drug, dasatinib (DAS), is used to treat prostate cancer, chronic myelogenous leukaemia, and acute lymphoblastic leukaemia. In the present work, we describe the preparation of zinc oxide (ZnO) nanoparticles (NPs) using Averrhoa bilimbi leaf extract. These ZnO NPs were combined with functionalized multi-walled carbon nanotubes (f-MWCNT) to prepare a ZnO@f-MWCNT nanocomposite for electrochemical sensing of DAS. The prepared electrode materials, ZnO NPs, f-MWCNT, and ZnO@f-MWCNT, were characterised by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), the Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), zeta potential, and the dynamic light scattering (DLS) techniques. DAS exhibited a significant enhancement (18-fold) in the oxidation peak current at ZnO@f-MWCNT, 10-fold at f-MWCNT, and 6-fold at ZnO NPs as compared to that at bare GCE. Under optimised conditions, a linear relationship was noticed among the peak current and concentration of DAS in the range of 0.03–82.65 μM and 0.01–122.45 μM for the differential pulse voltammetric (DPV), and square wave voltammetric (SWV) methods, respectively. Further, the applicability of the proposed sensor was demonstrated by analysing pharmaceutical and biological samples containing DAS. Higher percentage recovery values, and lower relative standard deviation (RSD) values highlighted the accuracy and precision proposed electrochemical methods.