Protein microarray scanning in label-free format by Kelvin nanoprobe.
Surface-immobilized protein species deposited in the microarray format have been detected by time-of-flight secondary ion mass spectrometry and by scanning Kelvin nanoprobe. The former method was used to examine the nature of protein deposition on amine-coated glass slides and gold substrates in preparation for Kelvin measurements. Both gallium and SF(5)(+) ion sources were employed to produce positive and negative ion spectra of amino acids and polypeptides. Scanning Kelvin technology has been used to detect antibody-antigen interactions in a label-free protocol through measurement of the surface potential of the biochemical pair on indium tin oxide, amine-treated slides and gold substrates. The results show that good inter-spot reproducibility can be achieved and that deposited areas can be examined for homogeneity at 100 nm resolution. This work represents the first report on surface potential detection in protein microarray technology.
Cheran
Larisa-Emilia
LE
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6. mikethom@chem.utoronto.ca
Chacko
Melissa
M
Zhang
Mingquan
M
Thompson
Michael
M
D013058:Mass Spectrometry / Q000379:methods; D036103:Nanotechnology / Q000379:methods*; D040081:Protein Array Analysis / Q000379:methods*; D013499:Surface Properties