Nickel-Based Metal-Organic Framework/Crosslinked Tubular Poly(3,4-ethylenedioxythiophene) Composite as an Electrocatalyst for the Detection of Gallic Acid and Tinidazole

Nickel-based metal-organic framework (Ni-MOF) embedded in tubular poly(3,4-ethylenedioxythiophene) (T-PEDOT) composites was first synthesized through the in situ growth of Ni-MOF with T-PEDOT. The incorporation of T-PEDOT and Ni-MOF enhances the conductivity of Ni-MOF/T-PEDOT, reduces aggregation and restricts the size of Ni-MOF, and exposes more active sites of the Ni-MOF. Compared with Ni-MOF, Ni-MOF/T-PEDOT manifests improved electrocatalytic activity toward the oxidation and reduction of gallic acid and tinidazole, respectively. The Ni-MOF/T-PEDOT-2/glassy carbon electrode (GCE) as a novel electrochemical sensor was constructed to detect two antibacterial drugs. Ni-MOF/T-PEDOT-2/GCE shows two linear responses to gallic acid in the range of 0.8-25.5 mu M and 25.5-150 mu M, with a high sensitivity of 0.559 mu A mu M-1. At the same time, Ni-MOF/T-PEDOT-2/GCE exhibits two linear responses to tinidazole in the range of 0.7-35 mu M and 35-255 mu M. Therefore, Ni-MOF/T-PEDOT-2/GCE could be used to detect gallic acid and tinidazole in real samples with satisfactory results. Recovery values varied from 95.1 to 104.2 % for gallic acid sensing and 94.2 to 104.2 % for tinidazole sensing, which demonstrates that the sensor has practical application for gallic acid and tinidazole detection. Our work offers an efficient strategy for fabricating a new electrocatalysts based on MOFs and tubular conductive polymer.