title: Luminescent Iridium(III) Complex Labeled DNA for Graphene Oxide-Based Biosensors.
abstract: There has been growing interest in utilizing highly photostable iridium(III) complexes as new luminescent probes for biotechnology and life science. Herein, iridium(III) complex with carboxyl group was synthesized and activated with N-hydroxysuccinimide, followed by tagging to the amino terminate of single-stranded DNA (ssDNA). The Ir-ssDNA probe was further combined with graphene oxide (GO) nanosheets to develop a GO-based biosensor for target ssDNA detection. The quenching efficiency of GO, and the photostability of iridium(III) complex and GO-Ir-ssDNA biosensor, were also investigated. On the basis of the high luminescence quenching efficiency of GO toward iridium(III) complex, the GO-Ir-ssDNA biosensor exhibited minimal background signals, while strong emission was observed when Ir-ssDNA desorbed from GO nanosheets and formed a double helix with the specific target, leading to a high signal-to-background ratio. Moreover, it was found that luminescent intensities of iridium(III) complex and GO-Ir-ssDNA biosensor were around 15 and 3 times higher than those of the traditional carboxyl fluorescein (FAM) dye and the GO-FAM-ssDNA biosensor after UV irradiation, respectively. Our study suggested the sensitive and selective Ir-ssDNA probe was suitable for the development of highly photostable GO-based detection platforms, showing promise for application beyond the OLED (organic light emitting diode) area.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
authors.forename: Qingcheng
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry, Biology and Material Engineering, Suzhou University of Science and Technology , Suzhou 215009, China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000032:analysis / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D049408:Luminescent Agents; D009942:Organometallic Compounds; D010087:Oxides; D007495:Iridium; D006108:Graphite