title: A novel fluorescent probe for copper ions based on polymer-modified CdSe/CdS core/shell quantum dots.
abstract: Quantum dots (QDs) have become one of the most attractive fields of current research because of their unique optical properties. Novel copper-sensitive fluorescent fluoroionophores based on CdSe/CdS core/shell QDs modified with a polymer of MAO-mPEG were synthesized and characterized in the present work. A pH of 6.47 was optimally selected for measurements. By modifying QDs with MAO-mPEG, significant aqueous fluorescence quenching was observed upon binding with copper ions involving both reduced and oxidized environments, indicating great sensitivity and specificity for copper-ion sensing. No significant interfering effects from other metal ions, such as Ag(+), Al(3+), Ba(2+), Ca(2+), Cd(2+), Co(2+), Cr(3+), Fe(2+), Fe(3+), Hg(2+), K(+), Mg(2+), Mn(2+), Na(+), Ni(2+), Pb(2+), Sn(2+), and Zn(2+), were observed. The linear response range for Cu(2+) was found to be 0.01-0.50 µM, and the limit of detection was evaluated to be 16 nM. The proposed method demonstrated improved sensitivity and selectivity characteristics for Cu(II) determinations based on CdSe/CdS core/shell QDs modified with MAO-mPEG by using a typical liquid-phase quenching assay, showing its potential application to multiplex sensing of different analytes through distinct ligand conjugation and functionalization of individual fluorophores.
authors.affiliation: Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha 410004, PR China. zhongcao04@yahoo.com.cn
authors.forename: Zhong
authors.initials: Z
authors.lastname: Cao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gu
authors.forename: Ju-Lan
authors.initials: JL
authors.lastname: Zeng
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Liu
authors.forename: Qin
authors.initials: Q
authors.lastname: Deng
authors.forename: Jun-Bing
authors.initials: JB
authors.lastname: Fan
authors.forename: Jian-Nan
authors.initials: JN
authors.lastname: Xiang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007477:Ions / Q000032:analysis; D011108:Polymers / Q000737:chemistry*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D007477:Ions; D011108:Polymers; D018036:Selenium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D003300:Copper; C058667:cadmium selenide