title: Bioconjugation of quantum-dots with chitosan and N,N,N-trimethyl chitosan.
abstract: Novel carbohydrate-based hybrids combining chitosan and chemically modified chitosan with CdS inorganic nanoparticles were designed and prepared via aqueous route at room temperature. N,N,N-trimethylchitosan (TM-chitosan) was synthesized aiming at substantially improving the water solubility of chitosan for producing stable colloidal systems. UV-vis spectroscopy, photoluminescence spectroscopy, Nuclear magnetic resonance spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the synthesis and the relative stability of biopolymer-capped CdS nanocrystals. The results have clearly indicated that chitosan and chitosan-derivative (TM-chitosan) were remarkably effective on nucleating and stabilizing CdS nanoparticles in aqueous suspensions. In addition, the CdS nanocrystals were produced in the so-called "quantum-size confinement regime", with the calculated average size below 3.5 nm and fluorescent activity in the visible range of the spectra. Therefore, a new single-step process was developed for the bioconjugation of quantum dots with water soluble chemically functionalized carbohydrates at room temperature for potential biomedical applications.
authors.affiliation: Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627 - Escola de Engenharia, Bloco 2 - Sala 2233, 31.270-901, Belo Horizonte, MG, Brazil.
authors.forename: Herman S
authors.initials: HS
authors.lastname: Mansur
authors.affiliation: Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627 - Escola de Engenharia, Bloco 2 - Sala 2233, 31.270-901, Belo Horizonte, MG, Brazil.
authors.forename: Alexandra A P
authors.initials: AA
authors.lastname: Mansur
authors.affiliation: Department of Chemistry, Federal University of Juiz de Fora, Campus Martelos, 36.036-330, Juiz de Fora, MG, Brazil.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Curti
authors.affiliation: Department of Chemistry, Federal University of Juiz de Fora, Campus Martelos, 36.036-330, Juiz de Fora, MG, Brazil.
authors.forename: Mauro V
authors.initials: MV
authors.lastname: De Almeida
mesh_terms: D048271:Chitosan / Q000138:chemical synthesis* / Q000378:metabolism; D055772:Green Chemistry Technology / Q000379:methods*; D045663:Quantum Dots / Q000737:chemistry* / Q000378:metabolism
chemical_list: C118071:N-trimethyl chitosan chloride; D048271:Chitosan