Transition Metal-Incorporated Fluorine-Doped Mesoporous Silica Nanoparticles for Non-Enzymatic Electrochemical Detection of Ascorbic Acid

Non-enzymatic electrochemical sensors for ascorbic acid require stable and efficient electrocatalysts. This study introduces fluorine-doped mesoporous silica nanoparticles (F-doped MSN) as a high-surface-area support for transition metal oxides (CoO, NiO, and CuO), enhancing their electrochemical performance against ascorbic acid detection. The synthesized materials were characterized using X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), and N2 adsorption-desorption measurements, the latter providing surface area, pore size, and pore volume information. The materials were subsequently fabricated onto nickel foam for amperometric analysis of ascorbic acid in 0.1 M KOH. Among the tested sensors, F-doped MSN/CoO exhibited superior performance, achieving a sensitivity of 985.34 mu A center dot mM1 center dot cm2, a 0.05 mu M limit of detection (LOD), and 0.17 mu M limit of quantification (LOQ). The sensor demonstrated a linear range from 50 mu M to 11 mM with high reproducibility, with a relative standard deviation (RSD) of 3.06%, and long-term stability over 45 days. Additionally, real sample analysis of commercial fruit juices demonstrated recovery rates ranging from 95.9% to 97.8%, further validating the sensor's accuracy for practical applications. These results establish F-doped MSN/CoO as a promising material for nonenzymatic electrochemical sensing of ascorbic acid in pharmaceutical and food industries.