Highly sensitive localized surface plasmon resonance immunosensor for label-free detection of HIV-1

A highly sensitive label-free immunosensor for the detection of HIV-1 is newly developed based on localized surface plasmon resonance (LSPR) method. Uniform nanopattern of circular Au-dots (10-20 nm) was fabricated on indium tin oxide (ITO) coated glass substrate by simple electrochemical deposition method. The surface of Au nanopattern was modified with HIV-1 neutralizing gp120 monoclonal antibody fragments. The modified substrate was employed to measure various concentrations of HIV-1 particles quantitatively based on the shift of longitudinal wavelength in the UV–Vis spectrum which results from the changes of local refractive index induced by specific antigen-antibody recognition events. The detection limit of the HIV-1 particles was estimated to be 200 fg/mL, which is 10 fold higher than that of previously reported virus detection method based on LSPR. Since fabricated LSPR immunosensor has high sensitivity and selectivity, it is a promising approach for biological/medical sample analysis and various kinds of virus detection.From the Clinical EditorA localized surface plasmon resonance-based virus detection method is shown to have an order of magnitude improvement in detectable concentration of HIV-1 particles. Similar approaches may be used for screening other viral particles as well.

Graphical AbstractIn this study, a highly sensitive HIV-1 particle detection sensor was developed by localized surface plasmon resonance (LSPR) method. Highly ordered circular shaped Au nanodot was fabricated by electrochemical deposition as a sensing layer and fragmented antibodies were coupled by gold and thiol (− SH) interaction. Based on the absorbance changes induced by specific antigen-antibody recognition events, HIV-1 virus like particles were quantitatively determined. The detection limit of the developed method was estimated at 200 fg/mL, which is 10 fold higher than that of previously reported virus detection method based on LSPR. Since fabricated LSPR sensor has high sensitivity and selectivity, it is a promising approach for biological/medical sample analysis and investigating interactions between biological molecules.Figure optionsDownload high-quality image (202 K)Download as PowerPoint slide