title: Study on the interaction between CdSe quantum dots and chitosan by scattering spectra.
abstract: Two different stabilizing agents thioglycolic acid (TGA) and L-cysteine (L-Cys) capped CdSe QDs with the diameter of 2 nm were synthesized, large amounts of stabilizing agents connected to CdSe QDs surface through Cd-S bond. The interaction between chitosan and QDs had been investigated, respectively. The interaction lead to the remarkable enhancement of RRS, RNLS and the enchantments were in proportional to the concentration of chitosan in a certain range. Under the optimal conditions, compared with TGA-CdSe QDs, the interaction between L-Cys-CdSe QDs with chitosan owned more broad linear range 0.042-3.0 microg mL(-1) and lower detect limits 1.2 ng mL(-1). The influences of factors on the interaction between chitosan with QDs and some foreign substances were all examined, which showed that the methods had a good sensitivity and selectivity. Based on this, it is hoped to build a method for the determination of chitosan using CdSe QDs as probes. Through Fourier transform infrared spectroscopy (FTIR) transmission electron microscopy (TEM), it was speculated that CdSe QDs interacted with chitosan to form a network structure aggregates through electrostatic attraction and hydrophobic forces. The reasons for the enhancement of RRS intensity were assumed as follows: resonance enhanced Rayleigh scattering effect, increase of the molecular volume, and hydrophobic effect.
authors.affiliation: Key Laboratory on Luminescence and Real-time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing 400715, PR China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Peng
authors.forename: Shaopu
authors.initials: S
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Zhengwen
authors.initials: Z
authors.lastname: Liu
authors.forename: Youqiu
authors.initials: Y
authors.lastname: He
mesh_terms: D019187:Cadmium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D046529:Microscopy, Electron, Transmission / Q000379:methods; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013499:Surface Properties; D013864:Thioglycolates / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013864:Thioglycolates; D048271:Chitosan; C058667:cadmium selenide; D003545:Cysteine