High Sensitivity Detection of Nitrite Electrochemical Sensor Modified with MOF Composite Materials

Abstract

Depositing composites of Ni-HHTP and MWCNTs on a glassy carbon electrode(GCE) have developed a sensitive and facile electrochemical sensor for nitrite detection. Ni-HHTP@MWCNTs composites were synthesized in situ using 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP), nickel acetate tetrahydrate Ni(OAc)2·4H2O and multi-walled carbon nanotubes (MWCNTs) by hydrothermal method. The composite electrode was prepared by the coating method. The synergistic combination of Ni-HHTP and MWCNTs enables the electrode to possess fast electronic conductivity and generate sensitive electrochemical signals for sodium nitrite (NaNO2). The controlled variable approach determines the best test conditions for the analyte and obtains a susceptible response signal. The composite electrode has an extensive linear response range of 1–10000 μM to NaNO2, with a detection limit of 0.95 μM and sensitivity of 0.96 mA·mM−1·cm−2, which shows excellent reproducibility and stability performance. There are no interferences from the most common ions. The electrochemical analysis method was used for nitrite detection in actual water samples with a recovery rate of 97.2%–103.7%, indicating this composite material’s practical application potential. The mechanism of the specific electrochemical process on the modified electrode was also explored. This work preliminarily explored new electrochemical sensors for high-precision nitrite detection and precise sensing in analysis tests.