Fabrication of a Novel Electrochemical Sensor Based on Carbon Cloth Matrix Functionalized with MoO₃ and 2D-MoS₂...

The preparation and characterization of a hybrid composite, based on carbon cloth (CC) matrix functionalized with two-dimensional (2D) MoS₂ flakes and MoO₃, and its use for developing an electrochemical sensor for the determination of riboflavin (RF) is here reported. The 2D-MoS₂-MoO₃CC composite was prepared by depositing 2D-MoS₂ nanosheets, obtained by liquid phase exfoliation (LPE), on the surface of a carbon cloth fiber network, previously functionalized with a layer of molybdenum oxide (α-MoO₃) by radio-frequency magnetron reactive sputtering technique. The 2D-MoS₂-MoO₃CC composite was characterized by scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX), and Raman spectroscopy. An electrochemical sensor has been then fabricated by fixing a slice of the 2D-MoS₂-MoO₃CC composite on the working electrode of a screen-printed carbon electrode (SPCE). The 2D-MoS₂-MoO₃-CC/SPCE sensor display good electrochemical characteristics which have been exploited, for the first time, in the electroanalytical determination of riboflavin (RF). The sensitivity to RF, equal to 0.67 µA mM^-1 in the linear range from 2 to 40 µM, and a limit of detection (LOD) of 1.5 µM at S/N = 3, demonstrate the promising characteristics of the proposed 2D-MoS₂-MoO₃-CC/SPCE electrochemical sensor for the determination of riboflavin.