Langmuir-Blodgett Nanoassemblies of the MoS₂-Au Composite at the Air-Water Interface for Dengue Detection

We report Langmuir-Blodgett (LB) films of molybdenum disulphide (MoS₂) and gold nanoparticles (AuNP) composite being utilized as a biosensing platform for dengue detection. The LB films of the MoS₂-AuNP composite have been transferred from the air-water interface to the indium tin oxide-coated glass substrate under optimized conditions. Further, antibodies specific to dengue NS1 antigen were immobilized onto these LB films. The fabricated immunosensor has been explored for NS1 antigen detection in standard samples as well as in spiked sera samples using electrochemical impedance spectroscopy. The NS1 antigen is present in the blood of infected persons from day one of the onset of clinical symptoms in primary dengue infection. The limit of detection for the standard and the spiked samples is found to be 1.67 and 1.19 ng mL^-1, respectively, which is suitable for clinical applications, as NS1 antigen levels in patient's sera range from 0.04 to 2 μg mL^-1 in primary infection and from 0.01 to 2 μg mL^-1 in secondary infection.