Novel Optical Nanobiosensor Based on Localized Surface Plasmon Resonance Assembled with Gold Colloid Nanoparticles

A novel optical biosensor assembled with gold colloidal nanoparticles on gold plate surface has been constructed via 1,4-dithiothreitol and L-cysteic acid for detection of bio-molecules like antigen, antibody protein and DNA plasmid, which exhibited distinct optical properties of localized surface plasmon resonance (LSPR). The prepared nano gold sol were characterized by using UV-Vis absorption spectroscopy, transmission electron microscopy (TEM), and cyclic voltammetry (CV), indicating that the Au colloidals were sphere-shaped and narrow-dispersed size distribution with a diameter of 24 plusmn 0.2 nm. It caused 2.80 nm of red shift in the peak wavelength (lambda_max) of LSPR spectrum for the nanosensor exposed to c-Myc (3C7) mouse monoclonal IgG and 3.36 nm of red shift to the corresponding antibody by the immuno-reaction subsequently. The LSPR nanobiosensor has been successfully applied to recognition of a DNA plasmid of pCMV-Myc Mammalian Expression Vector.