title: A cyclometalated iridium(III) complex used as a conductor for the electrochemical sensing of IFN-γ.
abstract: A novel iridium(III) complex was prepared and used as a conductor for sensitive and enzyme-free electrochemical detection of interferon gamma (IFN-γ). This assay is based on a dual signal amplification mechanism involving positively charged gold nanoparticles ((+)AuNPs) and hybridization chain reaction (HCR). To construct the sensor, nafion (Nf) and (+)AuNPs composite membrane was first immobilized onto the electrode surface. Subsequently, a loop-stem structured capture probe (CP) containing a special IFN-γ interact strand was modified onto the (+)AuNP surface via the formation of Au-S bonds. Upon addition of IFN-γ, the loop-stem structure of CP was opened, and the newly exposed "sticky" region of CP then hybridized with DNA hairpin-1 (H1), which in turn opened its hairpin structure for hybridizing with DNA hairpin-2 (H2). Happen of HCR between H1and H2thus generated a polymeric duplex DNA (dsDNA) chain. Meanwhile, the iridium(III) complex could interact with the grooves of the dsDNA polymer, producing a strong current signal that was proportional to IFN-γ concentration. Thus, sensitive detection of IFN-γ could be realized with a detection limit down to 16.3 fM. Moreover, satisfied results were achieved by using this method for the detection of IFN-γ in human serum samples.
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China.|Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Miao
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
authors.forename: Chung-Nga
authors.initials: CN
authors.lastname: Ko
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
authors.forename: Kasipandi
authors.initials: K
authors.lastname: Vellaisamy
authors.affiliation: School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China.
authors.forename: Zongbing
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Guanjun
authors.initials: G
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
authors.forename: Chung-Hang
authors.initials: CH
authors.lastname: Leung
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
authors.forename: Dik-Lung
authors.initials: DL
authors.lastname: Ma