title: A colorimetric gold nanoparticle sensor to interrogate biomolecular interactions in real time on a surface.
abstract: This paper presents a new label-free optical method to study biomolecular interactions in real time at the surface of an optically transparent substrate. The method relies on the change in the absorbance spectrum of a self-assembled monolayer of colloidal gold on glass, as a function of biomolecular binding to the surface of the immobilized colloids. Using this approach, we demonstrate proof of principle of a label-free optical biosensor to quantify biomolecular interactions in real time on a surface in a commercially available UV-visible spectrophotometer and of a colorimetric end-point assay using an optical scanner. The spectrophotometric sensor shows concentration-dependent binding and a detection limit of 16 nM for streptavidin. The sensor is easy to fabricate, is reproducible in its performance, has minimal technological requirements, namely, the availability of an UV-visible spectrophotometer or an optical scanner, and will enable high-throughput screening of biomolecular interactions in real time in an array-based format.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708-0281, USA.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Nath
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Chilkoti
mesh_terms: D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards; D001710:Biotin; D017979:Gold Colloid; D008024:Ligands; D036103:Nanotechnology / Q000379:methods*; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis; D019809:Streptavidin / Q000032:analysis
chemical_list: D017979:Gold Colloid; D008024:Ligands; D001710:Biotin; D019809:Streptavidin