Detection of analyte binding to microarrays using gold nanoparticle labels and a desktop scanner.
Microarray hybridization or antibody binding can be detected by many techniques, however, only a few are suitable for widespread use since many of these detection techniques rely on bulky and expensive instruments. Here, we describe the usefulness of a simple and inexpensive detection method based on gold nanoparticle labeled antibodies visualized by a commercial, office desktop flatbed scanner. Scanning electron microscopy studies showed that the signal from the flatbed scanner was proportional to the surface density of the bound antibody-gold conjugates, and that the flatbed scanner could detect six attomoles of antibody-gold conjugates. This detection system was used in a competitive immunoassay to measure the concentration of the pesticide metabolite 2,6-dichlorobenzamide (BAM) in water samples. The results showed that the gold labeled antibodies functioned comparably with a fluorescent based immunoassay for detecting BAM in water. A qualitative immunoassay based on gold-labeled antibodies could determine if a water sample contained BAM above and below 60-70 ng L(-1), which is below the maximum allowed BAM concentration for drinking water (100 ng L(-1)) according to European Union legislation.
BioArray Project, Mikroelektronik Centret (MIC), Technical University of Denmark (DTU), Oersteds Plads 345 East, DK-2800 Kongens Lyngby, Denmark.
Anpan
A
Han
Martin
M
Dufva
Erik
E
Belleville
Claus B V
CB
Christensen
D000911:Antibodies, Monoclonal; D002021:Buffers; D005455:Fluorescent Antibody Technique; D006046:Gold / Q000737:chemistry*; D007150:Immunohistochemistry; D007202:Indicators and Reagents; D008863:Microspheres; D010573:Pesticide Residues / Q000032:analysis; D040081:Protein Array Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
D000911:Antibodies, Monoclonal; D002021:Buffers; D007202:Indicators and Reagents; D010573:Pesticide Residues; D014874:Water Pollutants, Chemical; D006046:Gold