Enhanced biomolecular detection based on localized surface plasmon resonance (LSPR) using enzyme-precipitation reaction.
An enzyme-catalyzed precipitation reaction was employed as a means to increase the change in the LSPR signal after intermolecular bindings between antigens and antibodies occurred on gold nanodot surfaces. The gold nanodot array with an diameter of 175 nm and a thickness of 20 nm was fabricated on a glass wafer using thermal nanoimprint lithography. The human interleukin (hIL) 5 antibody was immobilized on the gold nanodot, followed by binding of hIL 5 to the anti-hIL 5. Subsequently, a biotinylated anti-hIL 5 and a alkaline phosphatase conjugated with streptavidin were simultaneously introduced. A mixture of 5-bromo-4-chloro-3-indolyl phosphate p-toluidine (BCIP) and nitro blue tetrazolium (NBT) was then used for precipitation, which resulted from the biocatalytic reaction of the alkaline phosphatase on gold nanodot. The LSPR spectra were obtained after each binding process. Using this analysis, the enzyme-catalyzed precipitation reaction on gold nanodots was found to be effective in amplifying the change in the peak wavelength of LSPR after molecular bindings.
Lee
Seung-Woo
SW
Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Korea.
Ahn
Junhyoung
J
Kim
Min-Gon
MG
Shin
Yong-Beom
YB
Lee
Jae Jong
JJ
Lim
Ki-Pil
KP
Kim
Ki-Bum
KB
D001704:Biopolymers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D011232:Chemical Precipitation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D008667:Metalloproteins / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D040081:Protein Array Analysis / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
D001704:Biopolymers; D008667:Metalloproteins