ENSAM: Europium Nanoparticles for Signal Enhancement of Antibody Microarrays on Nanoporous Silicon.
Publikation/Tidskrift/Serie: Journal of proteome research
To improve the sensitivity of antibody microarray assays, we developed ENSAM ( Europium Nanoparticles for Signal enhancement of Antibody Microarrays). ENSAM is based on two nanomaterials. The first is polystyrene nanoparticles incorporated with europium chelate (beta-diketone) and coated with streptavidin. The multiple fluorophores incorporated into each nanoparticle should increase signal obtained from a single binding event. The second nanomaterial is array surfaces of nanoporous silicon, which creates high capacity for antibody adsorption. Two antibody microarray assays were compared: ENSAM and use of streptavidin labeled with a nine-dentate europium chelate. Analyzing biotinylated prostate-specific antigen (PSA) spiked into human female serum, ENSAM yielded a 10-fold signal enhancement compared to the streptavidin-europium chelate. Similarly, we observed around 1 order of magnitude greater sensitivity for the ENSAM assay (limit of detection 10 (5)) compared to the streptavidin-europium chelate assay (limit of detection 10 (4)). Analysis of a titration series showed strong linearity of ENSAM ( R (2) = 0.99 by linear regression). This work demonstrates the novel utility of nanoparticles with time-resolved fluorescence for signal enhancement of antibody microarrays, requiring as low as 100-200 zmol biotinylated PSA per microarray spot. In addition, proof of principle was shown for analyzing PSA in plasma obtained from patients undergoing clinical PSA-testing.
- Medicine and Health Sciences
- ISSN: 1535-3893