DNA at aqueous/solid interfaces: chirality-based detection via second harmonic generation activity.
We present electronic spectra of single-strand and duplex DNA oligonucleotides covalently attached to fused quartz/aqueous interfaces and demonstrate that a strong nonlinear optical linear dichroism response is obtained when adenine and thymine bases undergo Watson-Crick base pairing to form a double helix. Complementary chi(3) charge screening studies indicate that the signal originates from 5 x 10(11) strands per square centimeter, or 6 attomoles of surface-bound oligonucleotides. The label-free, molecular-specific nature afforded by nonlinear optical studies of DNA at aqueous/solid interfaces allows for the real-time tracking of interfacial DNA hybridization for the first time.
Boman
Faith C
FC
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Gibbs-Davis
Julianne M
JM
Heckman
Laurel M
LM
Stepp
Brian R
BR
Nguyen
SonBinh T
ST
Geiger
Franz M
FM
D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry; D011791:Quartz / Q000737:chemistry*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry*
D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D014867:Water; D011791:Quartz; D004247:DNA