Structural, optical and sensing properties of CdS-NH(2)GO thin film as a dengue virus E-protein sensing material

摘要

Semiconductor nanoparticles, cadmium sulfide quantum dots composited with amine functionalized graphene oxide (CdS-NH(2)GO) were functionalized with specific monoclonal antibodies (IgM) based on surface plasmon resonance (SPR) optical sensor for the detection of dengue virus (DENV) E-protein. The SPR results suggested that DENV E-protein can be detected in the range 0.0001-10 nM with the binding affinity of 486.54 nM(-1). The successful binding between antibodies and antigens in an immunoassay sensor was further confirmed by Raman, UV-vis spectroscopy and atomic force microscopy (AFM). The Raman studies showed the depletion of protein molecules in the region of 120-1000 cm(-1), which gives an evidence for the binding of DENV E-proteins to the antibodies. From UV-vis spectra, the absorption band was red shifted upon binding of DENV E-protein. The AFM measurement further confirmed the interaction occurred between DENV E-protein and the Au/CdS-NH(2)GO/IgM sensor surface.