High-sensitivity ethanol sensor based on Co3O4/NiO/MXene nanocomposite-enhanced surface plasmon resonance

This study developed a surface plasmon resonance (SPR) ethanol sensor enhanced by a Co 3 O 4 /NiO/MXene nanocomposite. The Co 3 O 4 /NiO/MXene heterostructure was first synthesized via electrostatic self-assembly, and then immobilized onto the gold surface at varying concentrations through covalent bonding. The material’s high specific surface area and abundant active sites significantly enhanced ethanol adsorption, leading to a substantial amplification of the SPR response. Experimental results demonstrated optimal performance at a coating concentration of 1.5 mg/mL, achieving a sensitivity of 3216.20 nm/RIU. This represents a 36% enhancement compared to a conventional pure gold film sensor (2364.85 nm/RIU). Material characterization (SEM, XPS, XRD, BET) confirmed the successful synthesis of the composite and its porous structural properties. The sensor exhibits excellent linear response and high sensitivity, showing significant potential for application in ethanol detection.