Functionalized Cadmium-Metal Organic Framework Materials with Azo Bonds for Highly Sensitive Electrochemical Detection of 4-Aminophenol
The presence of 4-aminophenol(4-AP)in wastewater from the pharmaceutical industry is a common occurrence due to its role as a byproduct or intermediate during the hydrolysis process of paracetamol metabolism,resulting in significant water pollution.Therefore,it is crucial to employ a straightforward and reliable analytical approach for detecting 4-AP in the environment.In this study,a specific type of metal-organic framework(MOF)material called[Cd4(ABTC)2(H2O)12]n(SXNU-4-Cd,H4ABTC=3,3′,5,5′-azobenzene tetracarboxylic acid)was successfully synthesized,which exhibited a unique two-dimensional layered structure consisting of three intertwined spiral chains forming a distinctive″twist braid″.These layers underwent π-π stacking,creating three-dimensional channels with azo bonds decorating the channel walls.This p-π interaction significantly enhanced the adsorption capacity of SXNU-4-Cd towards 4-AP,thereby improving its recognition sensitivity.The fabricated SXNU-4-Cd/GCE sensor showed high sensitivity towards 4-AP in the linear concentration range of 0.1-130 μmol/L,with a detection limit of 8.6 nmol/L,and also exhibited good anti-interference capability,reproducibility and stability.The SXNU-4-Cd/GCE sensor was successfully used for detecting 4-AP in lake water sample,with spiked recoveries of 95.9%-102.8%.This study introduced a novel technique that utilized pure Cd-MOFs to develop electrochemical sensor capable of effectively detecting 4-AP in water samples.