Polyaniline-on-MOF Protects the MOF Structure During Carbonization for the Construction of a Portable Sensor to Detect tert-Butylhydroquinone

Abstract

Carbonization of metal-organic frameworks (MOF) often leads to structural collapse, which reduces porosity and specific surface area, limiting their application in electrochemical sensing. In this work, MOF-545@PANI composites have been synthesized by adsorbing aniline molecules onto the surface of MOF-545 and performing in-situ oxidative polymerization to grow polyaniline (PANI). The PANI shell formed on MOF-545 not only protects the MOF-545 framework during carbonization but also enhances electrical conductivity and specific surface area. Additionally, the carbon shell formed from PANI after high-temperature treatment effectively addresses the issue of its redox peaks interference within the potential window, which is conducive to the accurate display of the redox current signals of tert-butylhydroquinone (TBHQ). Using MOF-545@PANI-800, a high-performance portable sensor for TBHQ has been developed with a detection range of 0.03 to 100.0 μM and a limit of detection (LOD) of 12.6 nM. This portable sensor accurately detects TBHQ in food and environmental water samples, with results comparable to HPLC. Density functional theory (DFT) has been used to study the adsorption energy and charge density distribution of TBHQ on both MOF-545 and MOF-545@PANI-800. This breakthrough electrochemical detector provides valuable opportunities for creating smart, efficient, and portable monitoring solutions.