Electrodeposition of gold nanoparticles on Cu-based metal-organic framework for the electrochemical detection of nitrite

Herein, an electrochemical sensing platform based on Cu-based metal-organic framework (Cu-MOF) decorated with gold nanoparticles (AuNPs) is constructed for the sensitive detection of nitrite. Cu-MOF was synthesized by a simple wet chemical synthesis at room temperature. AuNPs were electrodeposited on Cu-MOF modified glass carbon electrode (Cu-MOF/GCE) using potentiostatic method. The AuNPs decorated Cu-MOF (Cu-MOF/Au) displays synergetic catalytic effect for the oxidation of nitrite due to the large surface area and porosity of Cu-MOF, which could prevent the aggregation of AuNPs and increase the adsorption of nitrite, combining with the high conductivity and excellent catalytic activity of AuNPs. A nitrite sensing platform was constructed based on Cu-MOF/Au/GCE, and amperometric technique was adopted for quantitative determination of nitrite. The prepared electrochemical sensing platform demonstrates high sensitivity, selectivity and good stability for the detection of nitrite. It shows two wide linear ranges of 0.1–4000 and 4000–10000 μM, and the low detection limit of 82 nM. Moreover, the sensing platform can also be used for the nitrite detection in real samples. This work would broaden the application of MOFs material in constructing more novel electrochemical sensing platforms.