title: Colloidal Au replacement assay for highly sensitive quantification of low molecular weight analytes by surface plasmon resonance.
abstract: A novel sensing method based on surface plasmon resonance (SPR) was developed for the highly sensitive quantification of low molecular weight (LMW) analytes (colloidal Au replacement assay). Gold nanoparticles (diameter = 20 nm) functionalized with lactosyl-poly(ethylene glycol) (PEG) were prepared and were specifically adsorbed onto a Ricinus communis agglutinin (RCA120)-immobilized SPR sensor chip surface. Subsequent injection of free d-galactose elicited the elution of the preadsorbed lactosyl-PEGylated gold nanoparticles in a manner proportional to the galactose concentration, achieving a substantial and quantitative analysis over a wide range of galactose concentrations (0.1-50 ppm). This method of d-galactose sensing through the substituted elution of preadsorbed nanoparticles from the sensor chip surface would be applicable for the highly sensitive SPR quantification of various LMW analytes, which are known to be difficult to detect by the conventional SPR sensing regime.
authors.affiliation: Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Takae
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nagasaki
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kataoka
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques; D003102:Colloids; D005690:Galactose / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D007785:Lactose / Q000737:chemistry; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D037121:Plant Lectins / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D003102:Colloids; D037121:Plant Lectins; C017707:Ricinus communis agglutinin-1; D011092:Polyethylene Glycols; D006046:Gold; D007785:Lactose; D005690:Galactose