Detection of protein analytes via nanoparticle-based bio bar code technology.
We describe a new format for the recently introduced bio bar code technology, which improves the dose response over 10,000-fold and thereby makes this technique analytically useful. Unlike other ultrasensitive protein detection methods, such as immuno-PCR or immuno-RCA, the bio bar code technique does not employ any enzymes to achieve detection limits in the attomolar range. By sandwiching a target between a magnetic bead and an amplifier nanoparticle, a multiplicity of bar code oligonucleotides are released for each captured target analyte. These surrogate bar code targets are then hybridized to microarrays and detected with silver-amplified gold nanoparticle probes. Using PSA detection as a model, we demonstrate a linear dose response over at least 4 orders of magnitude in both target concentration and concomitant signal and a 1000-fold improvement in detection limit compared to the best ELISA system.
Bao
Y Paul
YP
Nanosphere, Inc., 4088 Commercial Avenue, Northbrook, Illinois 60062, USA.
Wei
Tai-Fen
TF
Lefebvre
Phil A
PA
An
Hao
H
He
Liangxiu
L
Kunkel
Gregory T
GT
Müller
Uwe R
UR
D000911:Antibodies, Monoclonal / Q000737:chemistry; D000937:Antigen-Antibody Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006046:Gold / Q000737:chemistry*; D015336:Molecular Probe Techniques; D053758:Nanoparticles / Q000737:chemistry*; D017430:Prostate-Specific Antigen / Q000032:analysis*; D040081:Protein Array Analysis / Q000379:methods*; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D006046:Gold; D017430:Prostate-Specific Antigen