An electrochemical sensor for detecting nitrite at the picomolar level

The AuNPs-poly(PBA)-poly(Arg)-based electrochemical sensor was developed. • It exhibited a wide detection range (1.00 pM–10.00 μM) for nitrite. • It displayed an ultra-low limit of detection (0.17 pM). • This sensor showed rapid response, high selectivity, and excellent reproducibility. Excessive intake of nitrite (NO 2 − ) poses a serious threat to human health, so it is significantly important to develop rapid and sensitive detection methods for NO 2 − . In this study, an electrochemical sensor was constructed based on a glassy carbon electrode modified with a composite material consisting of gold nanoparticles-poly(phenylboronic acid)-poly(arginine) (AuNPs-poly(PBA)-poly(Arg)), which was constructed via a one-step in-situ electrochemical co-deposition strategy. The detection of NO 2 − was achieved using an iodine/iodide (I 2 /I − ) probe system. Under the optimal conditions, the sensor exhibited a wide linear detection range for NO 2 − from 1.00 pM to 10.00 μM with a limit of detection as low as 0.17 pM. Moreover, the applicability of the developed sensor was successfully demonstrated by determining NO 2 − levels in beef and surface water samples, yielding satisfactory recovery rates between 89.70% and 107.33%. This study provided a novel and effective approach for monitoring NO 2 − in food and environmental samples. Download: Download high-res image (66KB) Download: Download full-size image