MOF derived metal oxide nanohybrids with in situ grown rGO: a smart material for simultaneous electrochemical sensing of HQ and RS

Abstract

The untapped potential of electrochemical sensors based on metal–organic framework (MOF) derived metal oxides is still challenging in this globalization era to sense environmental pollutants. Herein, HKUST-1/rGO/CuO/α-Fe₂O₃ nanocomposites (NCs) have been fabricated via a single facile step of the hydrothermal process and utilized to modify the glassy carbon electrode (GCE) surface for simultaneous hydroquinone (HQ) and resorcinol (RS) detection. Electrochemical sensing is nevertheless hampered by the fact that MOFs have limited electrical conductivity, and their framework normally collapses upon calcination, which limits their applicability. MOFs can be used as a template and combined with other conductive materials to evade these pitfalls. The high electrocatalytic activity, increased surface area, abundant nanoscale interactions, and superb conductivity of these hybrids have efficiently increased redox reactions through their synergistic effect at the electrode surface. With a working potential of +0.39 V and +0.72 V (vs. Ag/AgCl electrode), the modified GCE exhibits great electro-oxidation for HQ and RS. The respective limits of detection (LODs) are 50 nM and 80 nM (S/N = 3) with 0.05–10 μM and 0.08–12 μM linear ranges, respectively. The sensing podium based on HKUST-1/rGO/CuO/α-Fe₂O₃ has also been employed to detect HQ and RS in skin whitening creams and hair toners to assess its practicability. Thus, we believe that this structural integration technique has much potential in material synthesis, energy storage, catalysis, and sensing.