Hybridization probe for femtomolar quantification of selected nucleic acid sequences on a disposable electrode.
Mixed monolayers of electroactive hybridization probes on gold surfaces of a disposable electrode were investigated as a technology for simple, sensitive, selective, and rapid gene identification. Hybridization to the ferrocene-labeled hairpin probes reproducibly diminished cyclic redox currents, presumably due to a displacement of the label from the electrode. Observed peak current densities were roughly 1000x greater than those observed in previous studies, such that results could easily be interpreted without the use of algorithms to correct for background polarization currents. Probes were sensitive to hybridization with a number of oligonucleotide sequences with varying homology, but target oligonucleotides could be distinguished from competing nontarget sequences based on unique "melting" profiles from the probe. Detection limits were demonstrated down to nearly 100 fM, which may be low enough to identify certain genetic conditions or infections without amplification. This technology has rich potential for use in field devices for gene identification as well as in gene microarrays.
Molecular Biosciences and Bioengineering, Plant and Environmental Protection Sciences, and Hawaii Natural Energy Institute, University of Hawaii, Honolulu, Hawaii 96822, USA. danielje@hawaii.edu
Daniel M
DM
Jenkins
Bilal
B
Chami
Matthias
M
Kreuzer
Gernot
G
Presting
Anne M
AM
Alvarez
Bor Yann
BY
Liaw
D000465:Algorithms; D001483:Base Sequence; D015374:Biosensing Techniques; D004563:Electrochemistry; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry; D005784:Gene Amplification; D006046:Gold / Q000737:chemistry*; D000075163:Metallocenes; D015336:Molecular Probe Techniques; D009693:Nucleic Acid Hybridization / Q000379:methods*; D015345:Oligonucleotide Probes; D017422:Sequence Analysis, DNA / Q000379:methods*; D013696:Temperature
D005296:Ferrous Compounds; D000075163:Metallocenes; D015345:Oligonucleotide Probes; D006046:Gold; C004998:ferrocene