title: A "Turn-on-off-on" fluorescence switch based on quantum dots and gold nanoparticles for discriminative detection of ovotransferrin.
abstract: A novel strategy for ovotransferrin (OVT) detection by tracing the "on-off-on" fluorescence signals of quantum dots (QDs) and gold nanoparticles (AuNPs) utilizing fluorescence measurements were established in this article. The immune interaction between QDs-OVT and anti-OVT-AuNPs leads to drastic quenching (turning off) of the donor by a fluorescence resonance energy transfer (FRET) process. After the addition of free OVT, anti-OVT-AuNPs peel off from the QDs-OVT surface and bind to free OVT due to competitive immunoreactions, resulting in the restoration of the fluorescence intensity of QDs (turning on). Consequently, this process can be utilized for the selective detection of OVT via optical responses. Under optimal conditions, the fluorescence intensity of the system increased linearly with increasing concentrations of OVT from 0.05 to 3.8 μg/mL. The limit of detection of OVT was 23.55 ng/mL. This method was applied to the analysis of OVT in egg powder samples. Furthermore, the strategy provided in this work could be conveniently followed to establish similar immunosensors for the rapid detection of other proteins with corresponding antibodies.
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
authors.forename: Yongguo
authors.initials: Y
authors.lastname: Jin
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
authors.forename: Xing
authors.initials: X
authors.lastname: Fu
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
authors.forename: Meihu
authors.initials: M
authors.lastname: Ma
authors.affiliation: National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China. Electronic address: caizhaoxia@mail.hzau.edu.cn.
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Cai
mesh_terms: D000818:Animals; D003207:Conalbumin / Q000032:analysis* / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D013696:Temperature
chemical_list: D003207:Conalbumin; D006046:Gold
keywords: Anti-ovotransferrin; Fluorescence resonance energy transfer; Ovotransferrin; “Turn-on-off-on” fluorescence switch