Aptamer-Au NPs conjugates-enhanced SPR sensing for the ultrasensitive sandwich immunoassay.
The goal of this work is to explore the amplification effect of aptamer-gold nanoparticles (Au NPs) conjugates for ultrasensitive detection of large biomolecules by surface plasmon resonance (SPR). A novel sandwich immunoassay is designed to demonstrate the amplification effect of aptamer-Au NPs conjugates by using human immunoglobulin E (IgE) as model analyte. Human IgE, captured by immobilized goat anti-human IgE on SPR gold film, is sensitively detected by SPR spectroscopy with a lowest detection limit of 1 ng/ml after anti-human IgE aptamer-Au NPs conjugates is used as amplification reagent. Meanwhile, the non-specific adsorption of aptamer-Au NPs conjugates on goat anti-human IgE is confirmed by SPR spectroscopy and then it is minimized by treating aptamer-Au NPs conjugates with 6-mercaptohexan-1-ol (MCH). These results confirm that aptamer-Au NPs conjugates is a powerful sandwich element and an excellent amplification reagent for SPR-based sandwich immunoassay.
Wang
Jianlong
J
Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States.
Munir
Ahsan
A
Li
Zhonghong
Z
Zhou
H Susan
HS
D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000276:immunology; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007073:Immunoglobulin E / Q000032:analysis* / Q000276:immunology; D053768:Metal Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*
D052157:Aptamers, Nucleotide; D007073:Immunoglobulin E; D006046:Gold