Self-Calibrating Electrochemical Sensors Based on Uniformly Dispersed Ag Nanoclusters in Nitrogen-Doped Carbon Sheets for Determination of Nitrite

In this work, in situ confinement polymerization was developed for the formation of silver nanoclusters (AgNCs) homogeneously distributed on nitrogen-doped carbon (NCS) utilizing N-vinyl functionalized imidazolium ionic liquids (ILs) as stabilizers and carbon precursors. The fabricated AgNC@NCSs exhibited excellent electrochemical and catalytic properties due to their controlled structure and morphology, the unique layered structure of the carbon carriers, and the confinement effect. The AgNC@NCS material was further fabricated for a printing electrode, which also acted as an internal reference for ratiometric and accurate detection. Nitrite was used as a target to verify the feasibility of self-calibrating detection at the AgNC@NCS printing electrode. The present electrochemical sensor demonstrated superior nitrite sensing characteristics, accompanied by a wide linear range (1.12-1400 mu M), low detection limit (0.38 mu M), high stability, and strong anti-interference ability. Importantly, high reliability of this self-calibrating detection was obtained for nitrate determination in food samples. Our work provides an efficient strategy for the design of self-calibrating electrodes in the area of electrochemical sensing.

Automated summary

In this work, silver nanoclusters (AgNCs) were uniformly distributed on nitrogen-doped carbon (NCS) using N-vinyl functionalized imidazolium ionic liquids (ILs) as stabilizers and carbon precursors through in situ confinement polymerization. The fabricated AgNC@NCSs exhibited excellent electrochemical and catalytic properties due to their controlled structure and morphology, the unique layered structure of the carbon carriers, and the confinement effect. Furthermore, the AgNC@NCS material was utilized to fabricate a printing electrode, which served as an internal reference for ratiometric and accurate detection, and demonstrated superior nitrite sensing characteristics.