title: The Influence of Surface Modification on the Photoluminescence of CdTe Quantum Dots: Realization of Bio-Imaging via Cost-Effective Polymer.
abstract: To impart biocompatibility, stability, and specificity to quantum dots (QDs)-and to reduce their toxicity-it is essential to carry out surface modification. However, most surface-modification processes are costly, complicated, and time-consuming. In addition, the modified QDs often have a large size, which leads to easy aggregation in biological environments, making it difficult to excrete them from in vivo systems. To solve these problems, three kinds of conventional polymers, namely, polyvinyl alcohol (PVA, neutral), sodium polystyrene sulfonate (PSS, negative charged), and poly(diallyl dimethyl ammonium chloride) (PDDA, positive charged) were selected to modify the surface of QDs at low cost via a simple process in which the size of the QDs was kept small after modification. The effect of polymer modification on the photoluminescence (PL) properties of the QDs was systematically investigated. High quantum yields (QYs) of 65 % were reached, which is important for the realization of bio-imaging. Then, the cytotoxicity of CdTe QD-polymer composites was systematically investigated via MTT assay using the Cal27 and HeLa cell lines, especially for high concentrations of QD-polymer composites in vitro. The experimental results showed that the cytotoxicity decreased in the order CdTe-PDDA>CdTe>CdTe-PSS>CdTe-PVA, indicating that PSS and PVA can reduce the toxicity of the QDs. An obvious cytotoxicity of CdTe-PVA and CdTe-PSS was present until 120 h for the Cal27 cell line and until 168 h for the HeLa cell line. At last, the Cal27 cell line was selected to realize bio-imaging using CdTe-PSS and CdTe-PVA composites with different emission colors under one excitation wavelength.
authors.affiliation: College of Chemistry, Northeast Normal University, Changchun, 130024, P. R. China.
authors.forename: Gan
authors.initials: G
authors.lastname: Jin
authors.affiliation: Department of Pediatric Dentistry, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, P. R. China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Jiang
authors.affiliation: College of Chemistry, Northeast Normal University, Changchun, 130024, P. R. China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Yi
authors.affiliation: College of Chemistry, Northeast Normal University, Changchun, 130024, P. R. China. sunhz335@nenu.edu.cn.
authors.forename: Hai-Zhu
authors.initials: HZ
authors.lastname: Sun
authors.affiliation: Department of Pathology, School of Stomatology, Jilin University, Changchun, 130021, P. R. China. hcsun@mail.jlu.edu.cn.
authors.forename: Hong-Chen
authors.initials: HC
authors.lastname: Sun
mesh_terms: D019187:Cadmium Compounds / Q000009:adverse effects / Q000737:chemistry* / Q000191:economics; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D049449:Luminescence; D057054:Molecular Imaging; D015394:Molecular Structure; D010316:Particle Size; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry* / Q000191:economics*; D045663:Quantum Dots / Q000009:adverse effects / Q000737:chemistry* / Q000191:economics; D013499:Surface Properties; D013691:Tellurium / Q000009:adverse effects / Q000737:chemistry* / Q000191:economics
chemical_list: D019187:Cadmium Compounds; D011108:Polymers; D013691:Tellurium; C028337:cadmium telluride
keywords: bio-imaging; cytotoxicity; photoluminescence; polymers; quantum dots