Abstract: Novel magnetic-antimicrobial-fluorescent multifunctional hybrid microspheres with well-defined nanostructure were synthesized by the aid of a poly(glycidyl methacrylate) (PGMA) template. The hybrid microspheres were fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and digital fluorescence microscope. The as-synthesized microspheres PGMA, amino-modified PGMA (NH 2-PGMA) and magnetic PGMA (M-PGMA) have a spherical shape with a smooth surface and fine monodispersity. M-PGMA microspheres are super-paramagnetic, and their saturated magnetic field is 4.608 emu·g ？1, which made M-PGMA efficiently separable from aqueous solution by an external magnetic field. After poly(haxemethylene guanidine hydrochloride) (PHGH) functionalization, the resultant microspheres exhibit excellent antibacterial performance against both Gram-positive and Gram-negative bacteria. The fluorescence feature originating from the quantum dot CdTe endowed the hybrid microspheres with biological functions, such as targeted localization and biological monitoring functions. Combination of magnetism, antibiosis and fluorescence into one single hybrid microsphere opens up the possibility of the extensive study of multifunctional materials and widens the potential applications. [1]Aleshina, E.Y; Yudanova, T.N; Skokova, I.F. Production and properties of polyvinyl alcohol spinning solutions containing protease C and polyhexamethylene guanidine. Fiber Chem. 2001, 33, 421–423. [2]Wei, D.F; Ma, Q.X; Guan, Y; Hu, F.Z; Zheng, A; Zhang, X; Teng, Z; Jiang, H. Structural characterization and antibacterial activity of oligoguanidine (polyhexamethylene guanidine hydrochloride). Mater. Sci. Eng. C 2009, 29, 1776–1780. [3]Hu, Y; Du, Y.M; Yang, J.H; Kennedy, J.F; Wang, X.H; Wang, L.S. Synthesis, characterization, and antibacterial activity of guanidinylated chitosan. Carbohydr. Polym. 2007, 67, 66–72. [4]Broxton, P; Woodcock, P.M; Heatley, F; Gilbert, P. Interaction of some polyhexamethylene biguanides and membrane phospholipids in Escherichia coli. J. Appl. Bacteriol. 1984, 57, 115–124. [5]Broxton, P; Woodcock, P.M; Gilbert, P. Binding of some polyhexamethylene biguanides to the cell envelope of Escherichia coli. Microbiology 1984, 41, 15–22. [6]Zhang, Y.M; Jiang, J.M; Chen, Y.M. Synthesis and antimicrobial activity of polymeric guanidine and biguanidine salts. Polymer 1999, 40, 6189–6198. [7]Guan, Y; Xian, H.N; Sullivan, H; Zheng, A. Antimicrobial-modified sulfite pulps prepared by in situ copolymerization. Carbohydr. Polym. 2007, 69, 688–696. [8]Kenawy, E; Worley, S.D; Broughton, R. The chemistry and applications of antimicrobial polymers: A state-of-the-art review. Biomacromolecules 2007, 8, 1359–1384. [9]Zou, H; Wu, S; Shen, J. Polymer/silica nanocomposites: Preparation, characterization, properties, and applications. Chem. Rev. 2008, 108, 3893–3957. [10]Qian, L.Y; Guan, Y; He, B.H; Xiao, H.N. Modified guanidine polymers: Synthesis and antimicrobial mechanism revealed by AFM. Polymer 2008, 49, 2471–2475. [11]Wang, Y; Maksimuk, S; Shen, R; Yang, H. Synthesis of γ-iron oxide nanoparticles using a freshly-made and recycled ionic liquid. Green Chem. 2007, 9, 1051–1056. [12]Shukoor, M.I; Natalio, F; Tahir, M.N; Ksenofontov, V; Therese, H.A; Theato, P; Schr？der, H.C; Müller, W.E.G; Tremel, W. Superparamagnetic γ-Fe2O3nanoparticles with tailored functionality for protein separation. Chem. Commun 2007, 4677–4679. [13]Yu, C.H; Lo, C.C.H; Tam, K; Tsang, S.C. Monodisperse binary nanocomposite in silica with enhanced magnetization for magnetic separation. J. Phys. Chem. C 2007, 111, 7879–7882. [14]Zhou, W; Yao, N; Yao, G; Deng, C; Zhang, X; Yang, P. Facile synthesis of aminophenylboronic acid-functionalized magnetic nanoparticles for selective separation of glycopeptides and glycoproteins. Chem. Commun. 2008, 5577–5579. [15]Wang, C.X; Yin, L.W; Zhang, L.Y; Kang, L; Wang, X.F; Gao, R. Magnetic (γ-Fe2O3@SiO2)n@TiO2 functional hybrid nanoparticles with actived photocatalytic ability. J. Phys. Chem. C 2009, 113, 4008–4011. [16]Kattnig, D.R; Rosspeintner, A; Grampp, G. Fully reversible interconversion between locally excited fluorophore, exciplex, and radical ion pair demonstrated by a new magnetic field effect. Angew. Chem. Int. Ed. 2008, 47, 960–962. [17]Qian, H.S; Hu, Y; Li, Z.Q; Yang, X.Y; Li, L.C; Zhang, X.T; Xu, R. ZnO/ZnFe2O4 magnetic fluorescent bifunctional hollow nanospheres: Synthesis, characterization, and their optical/magnetic properties. J. Phys. Chem. C 2010, 114, 17455–17459. [18]Wang, P; Shi, Q; Shi, Y; Clark, K.K; Stucky, G.D; Keller, A.A. Magnetic permanently confined micelle arrays for treating hydrophobic organic compound contamination. J. Am. Chem. Soc. 2009, 131, 182–188. [19]Uematsu, T; Kitajima, H; Kohma, T; Torimoto, T; Tachibana, Y; Kuwabata, S. Tuning of the fluorescence wavelength of CdTe quantum dots with 2 nm resolution by size-selective photoetching. Nanotechnology 2009, 20, 215302. :1–215302:9. [20]Horák, D. Magnetic polyglycidylmethacrylate microspheres by dispersion polymerization. J. Polym. Sci. A 2001, 39, 3707–3715. [21]Wang, W.C; Zhang, Q; Zhang, B.B; Li, D; Dong, X.Q; Zhang, L; Chang, J. Preparation of monodisperse, superparamagnetic, luminescent, and multifunctional PGMA microspheres with amino-groups. Chin. Sci. Bull. 2008, 53, 1165–1170. [22]Dong, X; Zheng, Y; Huang, Y; Chen, X; Jing, X. Synthesis and characterization of multifunctional poly(glycidyl methacrylate) microspheres and their use in cell separation. Anal. Biochem. 2010, 405, 207–212. [23]Sun, P; Zhang, H.Y; Liu, C; Fang, J; Wang, M; Chen, J; Zhang, J.P; Mao, C; Xu, S.K. Preparation and characterization of Fe3O4/CdTe magnetic/fluorescent nanocomposites and their applications in immuno-labeling and fluorescent imaging of cancer cells. Langmuir 2010, 26, 1278–1284. [24]Chen, Z.B; Sun, Y.L. N-halamine-based antimicrobial additives for polymers: Preparation, characterization, and antimicrobial activity. Ind. Eng. Chem. Res. 2006, 45, 2634–2640. [25]Lai, C; Wang, Y; Uttam, B.P; Chen, Y; Hsiao, J; Liu, C; Liu, H; Chen, C; Chou, P. One-pot solvothermal synthesis of FePt/Fe3O4core–shell nanoparticles. Chem. Commun. 2008, 5342–5344. [26]Liu, J; Zhang, L; Shi, S; Chen, S; Zhou, N; Zhang, Z; Cheng, Z; Zhu, X. A novel and universal route to SiO2-supported organic/inorganic hybrid noble metal nanomaterials via surface RAFT polymerization. Langmuir 2010, 26, 14806–14813. [27]Guo, J; Yang, W.L; Wang, C.C; He, J. Poly(N-isopropylacrylamide)-coated luminescent/magnetic silica microspheres: Preparation, characterization, and biomedical applications. Chem. Mater. 2006, 18, 5554–5562. [28]Krishanu, R; Ramachandram, B; Joseph, R.L. Metal-enhanced fluorescence from CdTe nanocrystals: A single-molecule fluorescence study. J. Am. Chem. Soc. 2006, 128, 8998–8999. [29]Cai, Z.S; Song, Z.Q; Yang, C.S; Shang, S.B; Yin, Y.B. Synthesis of 2-hydroxypropyl dimethylbenzylammonium N,O-(2-carboxyethyl) chitosan chloride and its antibacterial activity. J. Appl. Polym. Sci. 2009, 111, 3010–3015. [30]Qian, L.Y; Guan, Y; He, B.H; Xiao, H.N. Synergy of wet strength and antimicrobial activity of cellulose paper induced by a novel polymer complex. Mater. Lett. 2008, 62, 3610–3612. [31]Bao, H; Wang, E; Dong, S. One-pot synthesis of CdTe nanocrystals and shape control of luminescent CdTe-cystine nanocomposites. Small 2006, 2, 476–479.