Electrochemical Sensors Based on Metal-Organic Framework and Conductive Polymer HKUST-1@PANI for High-Performance Detection of Lead Ions

Abstract

In this research a highly microporous Cu-BTC (denoted as HKUST-1) was synthesized using a simple and rapid synthesis room temperature method. The as-prepared HKUST-1 obtained at room temperature for 10 min exhibited a very high Brunauer–Emmett–Teller (BET) surface area of 1875 m2/g, pore volume (Vp) of 0.789 cm3/g, and average micropore size of 7.84 Å. Based on this product, we successfully fabricated a conductive electrochemical sensor HKUST-1@PANI by polymerizing a conductive polyaniline polymer (PANI) around the metal-organic framework HKUST-1. Fourier transform infrared (FTIR) spectra, X-ray diffraction pattern (XRD) support the formation of HKUST-1@PANI. Furthermore, scanning electron microscopy (SEM) studies confirmed that PANI uniformly covered the surface of HKUST-1. We used the resulting material to build a new electrochemical sensor for the reliable detection of lead ions. The electrochemical response of the developed sensor towards ions was evaluated using differential pulse voltammetry (DPV). Under optimized conditions, linear detection was reproducible over the Pb2+ concentration range from 0.005 to 50 μM with a minimum detection limit of 5 nM. The sensor is practically usable in a wide variety of environments, as it is virtually immune to interference from other coexisting ions.