Label-free optical biosensor based on localized surface plasmon resonance of twin-linked gold nanoparticles electrodeposited on ITO glass.
A simple low-cost electrochemical approach has been used to directly deposit twin-linked gold nanoparticles (TGNPs) onto transparent indium tin oxide (ITO) coated film glass. The as-prepared TGNPs have a transverse localized surface plasmon resonance (LSPR) band at 540 nm and a longitudinal LSPR band at about 710 nm. The longitudinal LSPR band of TGNPs exhibits higher refractive index sensitivity (245 nm/RIU) than its transverse LSPR band. The resulting "clean" surface of the TGNPs is easy applied to the further modification. The subsequent bioconjugation of TGNP films with goat anti-mouse-immunoglobulin G (anti-m-IgG) is successfully employed for the detection of mouse-immunoglobulin G (m-IgG) in a model based on the specific binding affinity between the antigen and antibody. The spectrophotometric sensor shows concentration-dependent binding for m-IgG. This study reveals a simple and sensitive method to fabricate a label-free optical biosensor based on longitudinal LSPR band of TGNPs on ITO substrate.
Deng
Jiajia
J
College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou, Jiangsu 215123, PR China.
Song
Yan
Y
Wang
Yuan
Y
Di
Junwei
J
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D004595:Electroplating; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D007074:Immunoglobulin G / Q000097:blood*; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D055096:Optical Devices; D013194:Staining and Labeling / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D017971:Tin Compounds / Q000737:chemistry*
D007074:Immunoglobulin G; D017971:Tin Compounds; C109984:indium tin oxide; D006046:Gold