title: Highly specific colorimetric detection of DNA oxidation biomarker using gold nanoparticle/triplex DNA conjugates.
abstract: DNA oxidation causes a variety of diseases including cancer. The oxidized DNA nucleobases are excised by cellular repair enzymes and released into extracellular fluids. Specifically, the excised DNA oxidation product, such as 8-oxoGua, has been suggested as a biomarker for early cancer diagnosis. We previously developed an artificial receptor for the free base of 8-oxoGua on a triplex DNA backbone. The receptor contained a pre-organized cavity, which bounded 8-oxoGua with strong affinity and excellent selectivity over other nucleobases. However, accurate detection of 8-oxoGua in urine samples was affected by the presence of a large excess of guanine. Herein, we report a strategy to convert our receptor to a colorimetric biosensor by conjugating DNA strands to gold nanoparticles (GNP), specifically for 8-oxoGua. By simply incubating our sensor with a urine sample, 8-oxoGua can be detected at submicromolar concentrations with UV-vis spectrometer or even by naked eye.
authors.affiliation: Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, USA.
authors.forename: Xun
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Chemical, Biological, and Pharmaceutical Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
authors.forename: Yung-Hao
authors.initials: YH
authors.lastname: Tsou
authors.affiliation: Department of Chemical, Biological, and Pharmaceutical Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
authors.forename: Marina
authors.initials: M
authors.lastname: Garis
authors.affiliation: Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, USA. Electronic address: haidong.huang@njit.edu.
authors.forename: Haidong
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Chemical, Biological, and Pharmaceutical Engineering, New Jersey Institute of Technology, Newark, NJ, USA. Electronic address: xiaoyang@njit.edu.
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Xu
mesh_terms: D015415:Biomarkers; D015374:Biosensing Techniques; D003124:Colorimetry; D004247:DNA; D006046:Gold; D006801:Humans; D053768:Metal Nanoparticles; D053758:Nanoparticles; D010084:Oxidation-Reduction
chemical_list: D015415:Biomarkers; D006046:Gold; D004247:DNA
keywords: Colorimetric detection; DNA oxidation; DNA receptor; Nanoparticle