Nanocomposites consisting of copper and copper oxide incorporated into MoS4 nanostructures for sensitive voltammetric determination of bisphenol A

A nanocomposite (NC) of type Cu/Cu₂O/CuO@MoS₄ was obtained via coprecipitation and a hydrothermal approach from copper oxide nanoparticles and MoS₄ nanostructures. A series of nanocomposites has been fabricated with varying fractions of MoS₄. The NCs were characterized by XRD, XPS, SEM and TEM. The synergistic effect of enlarged specific surface, high electrocatalytic activity and the presence of mixed valencies strongly enhance the redox response at the interface of a glassy carbon electrode (GCE) modified with the NC. The intercalation properties of MoS₄ in the NCs result in outstanding electro-oxidative performance towards bisphenol A (BPA). The modified GCE, best operated at +0.16 V vs. SCE, has a linear response in the 0.0001 μM to 17 μM BPA concentration range (R² = 0.998) and high sensitivity (1587 mA μM⁻¹ cm⁻²). The sensor can detect BPA with very good selectivity, enhanced storage stability and a low detection limit of 0.10 nM (S/N = 3). This is the lowest value among the non-enzymatic biosensors reported until now. The sensor was used for real-time in-vitro monitoring of BPA in (spiked) serum samples.

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