Non-enzymatic electrochemical sensor based on ionic liquid [BMIM][PF6] functionalized zirconium‑copper bimetallic MOF composite for the detection of nitrite in food samples

In this study, we developed an electrochemical sensor utilizing a composite material consisting of zirconium‑copper bimetallic metal-organic framework functionalized with ionic liquid [BMIM][PF6]. This composite material was fabricated by simple wet impregnation method, which not only maintains excellent electrocatalytic activity but also enhances electron transfer rate and electroactive surface area. The ZrCu-MOF-818/ILs composite modified electrode has been demonstrated as an effective tool for the detection of nitrite. The electrode exhibited a remarkable limit of detection (LOD) of 0.148 μM and wide linear ranges of 6–3000 μM and 3000–5030 μM. It is worth noting that the sensor displayed excellent reproducibility and repeatability, with relative standard deviation (RSD) values of 1.06% and 1.37%, respectively. Furthermore, the proposed method was successfully applied for the detection of nitrite in tap water and pickle juice.