title: A novel fluorescent nanosensor for detection of heparin and heparinase based on CuInS2 quantum dots.
abstract: In this work, a novel fluorescence "turn off-on" nanosensor for the determination of heparin and heparinase based on CuInS2 quantum dots (QDs) was established. CuInS2 QDs (modified by l-cysteine) featuring amino groups were directly prepared in aqueous solution via a hydrothermal synthesis method. The amino groups on the surface of CuInS2 QDs can interact with sulfate and carboxylate groups in heparin via electrostatic interactions and hydrogen bonding, which led the fluorescence of CuInS2 QDs to "turn-off". However, the heparin could be hydrolyzed into small fragments in the presence of heparinase, which resulted in the fluorescence of CuInS2 QDs being recovered. Therefore, the addition of heparinase to the heparin/CuInS2 QDs system activated the fluorescence of CuInS2 QDs to "turn-on" state. Thus, the determination of heparin and heparinase could be achieved by monitoring the fluorescence "turn off-on". Under the optimum conditions, there was a good linear relationship between I/I0 (I and I0 were the fluorescence intensity of CuInS2 QDs in the presence and absence of heparin, respectively) and heparin concentration in the range of 0.05-15 μmol L(-1) with the detection limit of 12.46 nmol L(-1). The linear detection for heparinase was in the range of 0.2-5 μg mL(-1) with the detection limit of 0.07 μg mL(-1). The proposed nanosensor was employed for the detection of heparin in fetal bovine serum samples with satisfactory results.
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Ziping
authors: Z
authors: Liu
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Qiang
authors: Q
authors: Ma
authors: Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 230022, China.
authors: Xinyan
authors: X
authors: Wang
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Zihan
authors: Z
authors: Lin
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Hao
authors: H
authors: Zhang
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Linlin
authors: L
authors: Liu
authors: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China. Electronic address: suxg@jlu.edu.cn.
authors: Xingguang
authors: X
authors: Su
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D003300:Copper / Q000737:chemistry*; D006493:Heparin / Q000032:analysis* / Q000097:blood; D019763:Heparin Lyase / Q000032:analysis* / Q000097:blood; D007204:Indium / Q000737:chemistry*; D057230:Limit of Detection; D045663:Quantum Dots / Q000737:chemistry*; D044967:Serum / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013440:Sulfides / Q000737:chemistry*
chemical_list: D013440:Sulfides; D007204:Indium; D003300:Copper; D006493:Heparin; D019763:Heparin Lyase
keywords: CuInS(2) QDs; Electrostatic interaction; Fluorescence “turn off–on”; Heparin; Heparinase; Nanosensor