Designing and construction of carboxyl functionalised MWCNTs/Co-MOFs-based electrochemical sensor for the sensitive detection of nitrite

A simple and sensitive electrochemical sensor based on metal-organic framework carboxyl functionalised MWCNTs/Co-MOFs have been successfully fabricated towards nitrite detection. Electrochemical techniques such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) experiments were conducted on carboxyl functionalised MWCNTs/Co-MOFs electrochemical sensor to decipher the electrochemical sensing performance. Several important electrochemical sensor parameters have been evaluated for nitrite oxidation, such as pH, deposition potential and preconcentration time. The observed results showed that the proposed electrochemical sensor provide a wide linear working range i.e. 80–1160 µM with a detection limit (3σ) of 18.8 µM and sensitivity of 0.01 µA µm−1 cm−2. Furthermore, the proposed sensor also applied to determine the nitrite level in beverage and water samples with satisfactory recoveries.