Electrochemical Sensors for Sensitive and Selective Detection of Nitrite Based on Flexible Gold Microneedle Like Nanodendrites Modified Electrode

Abstract

In this study, we present a new approach utilizing Au nanodendrites (Au NDs) to modify flexible screen-printed carbon electrodes (FSPCEs), offering an efficient platform for voltammetric sensing of nitrite ions in food samples. The FSPCEs are created with gold leaf-like nanodendrites through a simple, one-step electrochemical deposition process. The direct growth of these Au NDs occurs efficiently on the carbon-paste electrode, eliminating the need for binders or additional reducing agents and organic solvents, owing to the aforementioned matrix. The modified electrodes serve as promising sensing platforms for nitrite detection. The outcomes demonstrated that a significant amount of AuNPs with dendritic morphologies were dispersed throughout the FSPCE.These novel flexible electrodes act as effective electrocatalyst for NO2− oxidation due to their large electrochemical active surface area (ECSA), well-dispersed Au nanostructures, and high electrical conductivity. The optimized sensor exhibits a wide linear response range from 0.02 to 5.8 µM, with 1.0 nM limit of detection, an impressive sensitivity of 52.529 µA µM−1 cm−2 and a quick current response time (< 3 sec) towards nitrite ions. Additionally, the suggested sensor demonstrates high selectivity, reproducibility, and stability. Furthermore, the FSPCEs are evaluated for their ability to selectively detect nitrite ions in various food samples such as tap water, drinking water, milk, and fruit juices, comparing the results with standard methods in real sample analysis. The fabricated sensors show promising potential for practical applications in food and environmental analysis. Consequently, Au NDs@FSPCE electrode emerged to be a novel platform for NO2− electrochemical detection. Because of their great affinity for analytical substances in solutions, gold nanodendrites supported on flexible screen-printed carbon electrodes (FSPCEs) are very useful for electrode modifications. Their increased effective surface area, which greatly raises the electrode's sensitivity and specificity for a range of analytical applications, is responsible for their high affinity.