title: A duplex DNA-gold nanoparticle probe composed as a colorimetric biosensor for sequence-specific DNA-binding proteins.
abstract: Using duplex DNA-AuNP aggregates, a sequence-specific DNA-binding protein, SQUAMOSA Promoter-binding-Like protein 12 (SPL-12), was directly determined by SPL-12-duplex DNA interaction-based colorimetric actions of DNA-Au assemblies. In order to prepare duplex DNA-Au aggregates, thiol-modified DNA 1 and DNA 2 were attached onto the surface of AuNPs, respectively, by the salt-aging method and then the DNA-attached AuNPs were mixed. Duplex-DNA-Au aggregates having the average size of 160 nm diameter and the maximum absorption at 529 nm were able to recognize SPL-12 and reached the equivalent state by the addition of ∼30 equivalents of SPL-12 accompanying a color change from red to blue with a red shift of the maximum absorption at 570 nm. As a result, the aggregation size grew to about 247 nm. Also, at higher temperatures of the mixture of duplex-DNA-Au aggregate solution and SPL-12, the equivalent state was reached rapidly. On the contrary, in the control experiment using Bovine Serum Albumin (BSA), no absorption band shift of duplex-DNA-Au aggregates was observed.
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea. jonghwa@gnu.ac.kr.
authors.forename: Junho
authors.initials: J
authors.lastname: Ahn
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea. jonghwa@gnu.ac.kr.
authors.forename: Yeonweon
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea. jonghwa@gnu.ac.kr.
authors.forename: Ae-Ree
authors.initials: AR
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea. jonghwa@gnu.ac.kr.
authors.forename: Joon-Hwa
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju 660-701, Korea. jonghwa@gnu.ac.kr.
authors.forename: Jong Hwa
authors.initials: JH
authors.lastname: Jung
mesh_terms: D000818:Animals; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D003124:Colorimetry / Q000379:methods*; D015342:DNA Probes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D013379:Substrate Specificity
chemical_list: D015342:DNA Probes; D004268:DNA-Binding Proteins; D006046:Gold