Sensitive electrochemical detection of total sugars in food using NiFe alloy nanowires

An innovative electrochemical sensor is introduced based on a nickel-iron (NiFe) alloy, designed for rapid, cost-effective, and straightforward sugar determination in food. The sensor features vertically aligned NiFe nanowire arrays, providing a high surface area for enhanced performance. Sensor calibration was performed for various mono- and disaccharide reducing sugars. In the linear range 0.05-0.3 mM, sensors exhibited a sensitivity of 0.642 µA µM⁻¹·cm⁻², with a detection limit of 2.57 µM for monosaccharides and a limit of quantification of 14 µM. In the same linear range, for disaccharides a sensitivity of 0.355 µA µM⁻¹·cm⁻², a detection limit of 4.62 µM and a limit of quantification of 14 µM were found. The sensors displayed excellent selectivity towards reducing sugars with negligible interference from glycerin, citric acid, Cu²⁺, K⁺, Na⁺, Cl^-, Ca²⁺, NO₃^-, Mg²⁺, SO₄^2-, uric acid, ascorbic acid, gallic acid and ethanol. Non-reducing sugars are also detectable following a simple sample pre-treatment step. Sensors were validated by measuring sugar concentrations in real samples (honey, fruit, milk, coke, juices, etc.), yielding recoveries above 96% thereby demonstrating robust selectivity against diverse interferents. These results were corroborated by conventional analysis techniques, showing excellent correlation. The proposed non-enzymatic nanowire sensor presents remarkable advantages, including exceptional stability and cost-effectiveness. It enables ultra-fast sugar detection in complex matrices, making it a powerful tool for food quality control and industrial process monitoring. This study report, for the first time, the effective application of NiFe nanowire arrays for total sugar quantification in food matrices. The developed sensors show outstanding performance compared with both enzymatic and non-enzymatic systems.