Rapid detection of caffeic acid in food beverages using a non-enzymatic electrochemical sensor based on a Bi2S3/CNF nanocomposite

Caffeic acid (CA), a naturally occurring polyphenol abundantly found in various plants, has garnered significant attention in recent years due to its diverse pharmacological properties and potential health benefits. Additionally, caffeic acid is used in a range of applications, including in the food industry, disease diagnostics, and environmental monitoring, underscoring the significance of its detection. In this investigation, Bi₂S₃/CNF nanocomposites were prepared by a simple ultrasonication method. The successful formation of the Bi₂S₃/CNF nanocomposites was validated through X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive electron microscopy (EDX), elemental mapping, Brunauer–Emmett–Teller (BET) studies and X-ray photoelectron microscopy (XPS). Furthermore, the electrochemical behaviour of CA on the resulting electrode was investigated through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Based on above findings, the non-enzymatic electrochemical sensor has good performance for the electrochemical detection of CA under tailored conditions; the wide linear range of CA concentrations detectable by the modified GCE was 0.1–500 μM, and the LOD was 108 nM, with the sensitivity of the modified GCE calculated to be 2.56 μA μM⁻¹ cm⁻² and good selectivity, repeatability, reproducibility and stability. Additionally, the Bi₂S₃/CNF/GCE nanocomposite electrode material was used to detect CA in real samples, such as apple and grape juice, and acceptable results were achieved showing good practical applicability. Ultimately, this study demonstrated that the suggested sensor has enhanced the ability to determine CA in food industry and health care field.