Alkaline earth metal stannate TSnO3 (T = Ca and Sr) entrapped functionalized carbon nanofiber composites: active electrocatalysts for the determination of hydroxychloroquine in environmental samples

Abstract

The modern revolution in the day-to-day lifestyle of the present world, outlooks for patients with severe acute respiratory syndrome (COVID-19), which stands hallmark for several autoimmune conditions, including rheumatic diseases that marks the aphorism “Sooner the Better” to treatments. From this viewpoint, hydroxychloroquine (HCQ) was recognized as a significant first-line agent and a potential choice for the clinical reliever. The long-term overexploitation of HCQ, however, poses significant health risks to humans and aquatic organisms, resulting in the contamination of water systems and impaired ecosystem functions. In this work, we synthesized thymol–menthol-based solvent-assisted synthesis of perovskite-type stannates TSnO₃ (T = Ca and Sr) via co-precipitation route and incorporated to functionalized carbon nanofibers (f-CNF) resulting in hierarchical CaSnO₃/f-CNF and SrSnO₃/f-CNF nanocomposite structures. By replacing conventional volatile toxic solvents with a sustainable green template (thymol–menthol NADES), the overall energy requirement is minimized, thus allowing the reaction to be carried out at lower temperatures. Structural characterization studies of the as-prepared samples revealed excellent surface and functional properties. The electrochemical behaviors were examined by CV using CaSnO₃/f-CNF and SrSnO₃/f-CNF-modified GCEs. When compared to SrSnO₃/f-CNF modified electrode, CaSnO₃/f-CNF revealed excellent electrochemical activity. This is due to the excellent snowflake-shaped morphology associated with rapid charge transfer associated with a large number of surface-active sites present in CaSnO₃/f-CNF. Significantly, the corresponding analytical curves exhibited a wide linear detecting range of 0.001–129.5 μM and a low detection limit of 4.5 nM. Significant recognition of HCQ in environmental samples at trace levels validates the practicability of the fabricated sensor.