Wet-chemically synthesis of SnO2-doped Ag2O nanostructured materials for sensitive detection of choline by an alternative electrochemical approach

Abstract

Here, a reliable electrochemical sensor prove was fabricated by SnO2-doped Ag2O nanorods (NRs) decorated glassy carbon electrode (GCE) to detect choline (CA) in the buffer phase. The wet-chemically synthesized SnO2-doped Ag2O NRs were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques respectively. SnO2-doped Ag2O NRs was layered as a film of NRs onto a GCE using Nafion adhesive to obtain the working electrode of the choline (CA) sensor. The proposed sensor is calibrated by using the concentration of CA versus measured current, which is found linear over a concentration range of CA (0.1 nM ~ 0.01 mM) defined as a dynamic range (LDR) for choline detection. Using LDR slope and the active surface of GCE (0.0316 cm2), the choline sensor sensitivity (95.1 µAµM-1cm−2) is calculated. The limit of detection (LOD) and limit of quantification (LOQ) of the proposed CA sensor are calculated using the signal-to-noise ratio at 3, and the obtained values are 95.9 ± 4.8 pM and 319.67 ± 5 pM respectively. The sensor reliability measuring parameters (response time, stability and reproducibility) are found satisfactory. In the end, the choline sensor with SnO2-doped Ag2O NRs/GCE is performed preciously in the electrochemical analysis of various real bio-samples to validate its real-time applicability.