2D-V₂CTx MXene coupled with molecular imprinting: A highly sensitive and green electrochemical sensor for trace cholesterol detection

Cardiovascular and metabolic problems are closely linked to aberrant cholesterol (CHO) levels, an important biomolecule involved in many physiological processes. The precise and sensitive determination of CHO in biological matrices is therefore crucial for therapeutic purposes. In this work, two-dimensional V₂CTx MXene nanosheets (2D V₂CTx MXene) were incorporated into a molecularly imprinted polymer (MIP)-based electrochemical sensor for the detection of CHO with high sensitivity and selectivity. To improve electrical conductivity and surface area, a glassy carbon electrode (GCE) was modified with 2D V₂CTx MXene. This was followed by electropolymerization (EP) using indazole-6-boronic acid (I-6BA) as the functional monomer and aniline (ANI) as the co-monomer in the presence of the CHO template. To maximize analytical performance, important experimental parameters were systematically optimized, including the template-to-monomer ratio, the number of EP cycles, the removal solution, the removal time, and the rebinding time. Using scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), the successful creation of particular recognition cavities and the electrochemical properties of the sensor were characterized. The suggested MIP-based sensor demonstrated a broad linear response range from 1.0 × 10⁻¹³ M to 1.0 × 10⁻¹² M under ideal conditions, with an ultralow limit of detection (LOD) of 2.80 × 10⁻¹⁴ M. Even in the presence of potentially interfering agents, the sensor showed good selectivity toward CHO. Additionally, real patient plasma samples were used to successfully validate its applicability, yielding recovery percentages of 99.50 %–102.39 %. Moreover, the 2D V₂CTx MXene-supported MIP-based electrochemical sensor provides a highly sensitive, selective, and economical analytical platform for the determination of CHO. For clinical and biomedical applications, the proposed technology is a promising alternative to traditional analytical methods due to its straightforward fabrication process, high reproducibility, and reliable performance in complex biological matrices. In addition, the suggested sensor was assessed using the Analytical GREEnness Metric Approach (AGREE) and the Analytical Greenness Assessment Tool for Molecularly Imprinted Polymers Synthesis (AGREE-MIP), which confirmed its strong compliance with Green Analytical Chemistry principles through low energy requirements, minimal waste generation, reduced reagent consumption, and environmentally benign fabrication steps.