Ultrasensitive and rapid electrochemical detection of nitrite based on gold nanoparticles-poly(phenylboronic acid) modified electrode and I2/I− probe

A novel electrochemical sensor based on gold nanoparticles-poly(phenylboronic acid)/glass carbon electrode (AuNPs-poly(PBA)/GCE) was successfully constructed for detecting nitrite (NO 2 − ) ions using the iodine/iodide (I 2 / I − ) mixed system as a probe. The AuNPs-poly(PBA) composites were firstly prepared on a bare GCE by one-step electrodeposition. By combining the specific enrichment ability of poly(PBA) to NO 2 − and I 2 / I − with the catalytic activity of AuNPs to the reaction between them, the response range of this sensor towards NO 2 − was 1.0 × 10 −11  M to 1.0 × 10 −4  M with a limit of detection (LOD) of 1.7 × 10 −12  M (S/N = 3). The sensor had the advantages of easy preparation, fast response, wide linear range, low LOD, and good selectivity, and could be applied to detect NO 2 − in beef and tap water samples with satisfactory results, which provided a highly sensitive and rapid analysis approach in the fields of food safety and environmental monitoring.