Fabrication of DNA microarrays with poly(L-glutamic acid) monolayers on gold substrates for SPR imaging measurements.
Robust single-stranded DNA (ssDNA) microarrays are created by attaching amine-modified oligonucleotides to a monolayer of poly(L-glutamic acid) (pGlu) that is electrostatically adsorbed onto a chemically modified gold thin film. This surface attachment chemistry methodology is first characterized with a combination of polarization-modulation Fourier transform infrared (PM-FTIR) spectroscopy and surface plasmon resonance (SPR) angle shift measurements. SPR imaging (SPRI) measurements of these ssDNA microarrays are then used to study two surface bioaffinity interactions: (i) the quantitative hybridization adsorption of complementary ssDNA onto mixed ssDNA microarray elements and (ii) the adsorption of single-stranded binding protein (SSB) onto fully and partially hybridized DNA microarray elements. The Langmuir adsorption coefficient (K(Ads)) of SSB binding to ssDNA was determined to be (5.5 +/- 0.4) x 10(9) M(-1).
Chen
Yulin
Y
Department of Chemistry, University of California--Irvine, Irvine, California 92697, USA.
Nguyen
Anh
A
Niu
Lifang
L
Corn
Robert M
RM
D000327:Adsorption; D006046:Gold / Q000737:chemistry*; D015394:Molecular Structure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D011099:Polyglutamic Acid / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
D011099:Polyglutamic Acid; D006046:Gold