Polysaccharides derived from Ganoderma lucidum applied to the extraction chitosan and development of electrochemical sensor based on extracted chitosan and graphitic carbon nitride modified electrode for determination nitrite in food samples

Abstract

The current study focused on extracting chitosan from polysaccharides generated from Ganoderma lucidum and applying it to the construction of electrochemically modified electrodes based on graphitic carbon nitride (g-C3N4) for the measurement of nitrite in water and food samples. Ganoderma Lucidum polysaccharides were isolated and characterized. The chitosan was then isolated enzymatically from the polysaccharides using a chemical technique. The isolated chitosan and g-C3N4 were used to modify a GCE (chitosan/g-C3N4/GCE). The structural investigations employing FT-IR, SEM, and XRD show that chitosan successfully interacted with g-C3N4 in the chitosan/g-C3N4 sample. Electrochemical evaluation using cycle voltammetry (CV), differential pulse voltammetry (DPV), and amperometry revealed that the chitosan/g-C3N4/GCE electrode has good sensitivity and selectivity for determining nitrite. The use of chitosan and g-C3N4 in electrode surface modification improved nitrite electro-oxidation performance by allowing for more effective adsorption and electron transport processes. DPV measurement showed that the sensor had a sensitivity of 0.12103 μA/μM, a linear range of 40 to 2000 μM, and a limit of detection of 21 nM, and amperometry measurement showed the sensor's sensitivity of 0.15487 μA/μM, linear range of 20 to 4230 μM, and an LOD of 10 nM. These findings indicated a more sensitive and wide range of sensor performance using amperometry with respect to the DPV technique. The method's validity and accuracy in determining nitrite in prepared genuine samples (water, milk, apple juice, orange juice, Aloe vera, and tomato juice) were investigated. RSD values (3.19 % to 4.75 %) and recovery values (80.00 % to 98.33 %) were found to be satisfactory. The data also revealed that there were no substantial matrix interferences, demonstrating the accuracy and applicability of the proposed approach for detecting nitrite in food samples. Therefore, the proposed sensor design has several advantages that make it a promising candidate for various applications. Its reusability, stability, wide linear range, accuracy, and low cost make it an attractive option for many industries.