title: A label-free fluorescent assay for deoxyribonuclease I activity based on DNA-templated silver nanocluster/graphene oxide nanocomposite.
abstract: A novel label-free system for the sensitive fluorescent detection of deoxyribonuclease I (DNase I) activity has been developed by utilizing DNA-templated silver nanocluster/graphene oxide (DNA-AgNC/GO) nanocomposite. AgNC is first synthesized around C-rich template DNA and the resulting DNA-AgNC binds to GO through the interaction between the extension DNA and GO. The resulting DNA-AgNC/GO would show quite reduced fluorescence signal because the fluorescence from DNA-AgNCs is quenched by GO. In the presence of DNase I, however, it degrades the DNA strand within DNA/RNA hybrid duplex probe employed in this study, consequently releasing RNA which is complementary to the extension DNA. The released free RNA then extracts DNA-AgNC from GO by hybridizing with the extension DNA bound to GO. This process would restore the quenched fluorescence, emitting highly enhanced fluorescence signal. By employing this assay principle, DNase I activity was reliably identified with a detection limit of 0.10U/ml which is lower than those from previous fluorescence-based methods. Finally, the practical capability of this assay system was successfully demonstrated by its use to determine DNase I activity in bovine urine.
authors: Department of Chemical and Biomolecular Engineering (BK 21+ program), KAIST, Daehak-ro 291, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors: Chang Yeol
authors: CY
authors: Lee
authors: Department of Chemical and Biomolecular Engineering (BK 21+ program), KAIST, Daehak-ro 291, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors: Ki Soo
authors: KS
authors: Park
authors: Department of Energy and Chemical Engineering, UNIST, UNIST-gil 50, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea.
authors: Yun Kyung
authors: YK
authors: Jung
authors: Department of Chemical and Biomolecular Engineering (BK 21+ program), KAIST, Daehak-ro 291, Yuseong-gu, Daejeon 305-701, Republic of Korea. Electronic address: hgpark@kaist.ac.kr.
authors: Hyun Gyu
authors: HG
authors: Park
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D004247:DNA / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D003850:Deoxyribonuclease I / Q000737:chemistry / Q000302:isolation & purification* / Q000652:urine; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D010087:Oxides / Q000737:chemistry*; D012313:RNA / Q000737:chemistry; D012834:Silver
chemical_list: D015342:DNA Probes; D010087:Oxides; D012834:Silver; D012313:RNA; D006108:Graphite; D004247:DNA; D003850:Deoxyribonuclease I
keywords: DNA-templated silver nanocluster; Deoxyribonuclease I; Fluorescent enzyme assay; Graphene oxide; Nanocomposite; RNA/DNA hybrid