title: Fluorescent-magnetic dual-encoded nanospheres: a promising tool for fast-simultaneous-addressable high-throughput analysis.
abstract: Bead-based optical encoding or magnetic encoding techniques are promising in high-throughput multiplexed detection and separation of numerous species under complicated conditions. Therefore, a self-assembly strategy implemented in an organic solvent is put forward to fabricate fluorescent-magnetic dual-encoded nanospheres. Briefly, hydrophobic trioctylphosphine oxide-capped CdSe/ZnS quantum dots (QDs) and oleic acid-capped nano-γ-Fe2O3 magnetic particles are directly, selectively and controllably assembled on branched poly(ethylene imine)-coated nanospheres without any pretreatment, which is crucial to keep the high quantum yield of QDs and good dispersibility of γ-Fe2O3. Owing to the tunability of coating amounts of QDs and γ-Fe2O3 as well as controllable fluorescent emissions of deposited-QDs, dual-encoded nanospheres with different photoluminescent emissions and gradient magnetic susceptibility are constructed. Using this improved layer-by-layer self-assembly approach, deposition of hydrophobic nanoparticles onto hydrophilic carriers in organic media can be easily realized; meanwhile, fluorescent-magnetic dual-functional nanospheres can be further equipped with readable optical and magnetic addresses. The resultant fluorescent-magnetic dual-encoded nanospheres possess both the unique optical properties of QDs and the superparamagnetic properties of γ-Fe2O3, exhibiting good monodispersibility, huge encoding capacity and nanoscale particle size. Compared with the encoded microbeads reported by others, the nanometre scale of the dual-encoded nanospheres gives them minimum steric hindrance and higher flexibility.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Research Center for Nanobiology and Nanomedicine (MOE 985 Innovative Platform), State Key Laboratory of Virology, and Wuhan Institute of Biotechnology, Wuhan University, Wuhan, 430072, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Xie
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Cong-Ying
authors.initials: CY
authors.lastname: Wen
authors.forename: Zhi-Ling
authors.initials: ZL
authors.lastname: Zhang
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Xie
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D057166:High-Throughput Screening Assays / Q000379:methods; D059346:Magnets / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D019301:Oleic Acid / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D005290:Ferric Compounds; D005456:Fluorescent Dyes; D009943:Organophosphorus Compounds; C000499:ferric oxide; D019301:Oleic Acid; C044965:trioctyl phosphine oxide; D011094:Polyethyleneimine