title: A simple fluorescent biosensor for theophylline based on its RNA aptamer.
abstract: Theophylline is a potent bronchodilator with a narrow therapeutic index. A simple fluorescent biosensor that detects clinically relevant theophylline concentrations has been developed using the well-characterized theophylline binding RNA aptamer. Hybridization of the RNA aptamer to a fluorescently labeled DNA strand (FL-DNA) yields a fluorescent RNA:DNA hybrid that is sensitive to theophylline. The biosensor retains the remarkable selectivity of the RNA aptamer for theophylline over caffeine and is sensitive to 0-2 muM theophylline, well below the clinically relevant concentration (5-20 mg/L or approximately 10-50 muM). Adding a dabcyl quenching dye to the 3'-terminus of the fluorescently labeled DNA strand yielded a dual-labeled DNA strand (FL-DNA-Q) and increased the dynamic range of this simple biosensor from 1.5-fold to 4-fold.
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina-Greensboro, Greensboro, North Carolina 92110, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Rankin
authors.forename: E N
authors.initials: EN
authors.lastname: Fuller
authors.forename: K H
authors.initials: KH
authors.lastname: Hamor
authors.forename: S A
authors.initials: SA
authors.lastname: Gabarra
authors.forename: T P
authors.initials: TP
authors.lastname: Shields
mesh_terms: D052157:Aptamers, Nucleotide / Q000138:chemical synthesis / Q000737:chemistry*; D015374:Biosensing Techniques; D002110:Caffeine / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000494:pharmacology*; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013806:Theophylline / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D002110:Caffeine; D012313:RNA; D004247:DNA; D013806:Theophylline