镉(Ⅱ)-半胱氨酸配合物对CdS量子点的荧光增强作用及其在离子检测中的应用

doi:10.11944/j.issn.1000-0518.2015.08.140418

摘要/Abstract

摘要：

合成了弱配体柠檬酸三钠修饰的CdS量子点(Cit-CdS QDs), 透射电子显微镜表征结果表明, Cit-CdS QDs的粒径分布均匀(4~6 nm), 分散性好。研究了金属离子(银(Ⅰ)离子、镉(Ⅱ)离子)、巯基化合物(巯基乙酸、半胱氨酸)以及金属离子(银(Ⅰ)离子、镉(Ⅱ)离子)与巯基化合物形成的配合物对Cit-CdS QDs荧光的影响。发现金属离子(银离子、镉离子)与巯基化合物(巯基乙酸、半胱氨酸)形成的水溶性配合物可以显著增强Cit-CdS QDs的荧光, 配合物对Cit-CdS QDs的增强程度比单独的金属离子或巯基化合物均要高, 而且配合物修饰的CdS QDs对铜(Ⅱ)离子的响应要高于单独用金属离子或巯基化合物修饰的量子点。建立了铜(Ⅱ)离子高灵敏度荧光检测方法, 该方法检测范围宽(1.0×10^-8~1.0×10^-6 mol/L), 检测限低(1.0×10^-9 mol/L)且具有很好的选择性, 拓展了配合物作为量子点修饰剂的应用。

关键词: 量子点, 荧光, 铜离子, 传感器, 配合物

Abstract:

CdS quantum dots capped by citrate(Cit-CdS QDs) were synthesized in aqueous solution. TEM analysis indicates that the Cit-CdS QDs are well-dispered with the diameter of 4 to 6 nm. The influence of silver(Ⅰ), cadmium(Ⅱ), thioglycolic acid, cysteine and the complexes formed by silver(Ⅰ)/cadmium(Ⅱ) with the thiol compounds(thioglycolic acid or cysteine) on the fluorescence of Cit-CdS QDs was investigated. All above modifiers can enhance the fluorescence intensity of Cit-CdS QDs. The complexes above have much greater fluorescence enhancement effect than that of the solely metal ions or thiol compounds. In addition, the CdS QDs modified by the complexes also have much higher sensitivity for copper(Ⅱ) sensing. Based on this phenomenon, a highly sensitive and selective fluorescence probe for Cu²⁺ was developed with a wide range of 1.0×10^-8~1.0×10^-6 mol/L and a low detection limit of 1.0×10^-9 mol/L. It may open up new opportunity for the synthesis and application of complex modified quantum dots in analytical chemistry.

Key words: quantum dots, fluorescence, copper(Ⅱ) ion, sensor, complex

中图分类号:

吴秀明, 金璐怡, 徐意, 王光丽. 镉(Ⅱ)-半胱氨酸配合物对CdS量子点的荧光增强作用及其在离子检测中的应用[J]. 应用化学, 2015, 32(8): 969-976.

WU Xiuming, JIN Luyi, XU Yi, WANG Guangli. Enhanced Fluorescence of CdS Quantum Dots by Cadmium(Ⅱ)-Cysteine and Its Application in Ion Detection[J]. Chinese Journal of Applied Chemistry, 2015, 32(8): 969-976.

参考文献

[1]	Lou Y B, Zhao Y X, Chen J X. Metal Ions Optical Sensing by Semiconductor Quantum Dots[J]. J Mater Chem C, 2014, 2:595-613.
[2]	Turrilas F A E, Fuentes A A. Applications of Quantum Dots as Probes in Immunosensing of Small-sized Analytes[J]. Biosens Bioelectron, 2013, 41:12-29.
[3]	Liu S Y, Su X G. The Synthesis and Application of Doped Semiconductor Nanocrystals[J]. Anal Methods, 2013, 5:4541-4548.
[4]	Petryayeva E, Algar W R, Krull U J. Adapting Fluorescence Resonance Energy Transfer with Quantum Dots Donors for Solid-phase Hybridization Assays in Microtiter plate Format[J]. Langmuir, 2013, 29:977-988.
[5]	Qin L X, Ji C C, He L W, et al.Interactions between Quantum Dots and Dopamine Coupled via a Peptide Bridge[J]. RSC Adv, 2014, 4:2143-2150.
[6]	Spanhel L, Haase M, Weller H, et al.Surface Modification and Stability of Strong Luminescing CdS particles[J]. J Am Chem Soc, 1987, 109(19):5649-5655.
[7]	Sooklal K, Cullum B S, Angel S M, et al.Photophysical Properties of ZnS Nanoclusters with Spatially Localized Mn2+[J]. J Phys Chem, 1996, 100(11):4551-4555.
[8]	Moore D E, Patel K. Q-CdS Photoluminescence Activation on Zn2+ and Cd2+ Salt Introduction[J]. Langmuir, 2001, 17(8):2541-2544.
[9]	Chen Y F, Rosenzweig Z. Luminescent CdS Quantum Dots as Selective Ion Probes[J]. Anal Chem, 2002, 74(19):5132-5138.
[10]	Wang G L, Jiao H J, Zhu X Y, et al.Enhanced Fluorescence Sensing of Melamine Based on Thioglycolic Acid-capped CdS Quantum Dots[J]. Talanta, 2012, 93:398-403.
[11]	Wang H F, He Y, Ji T R, et al.Surface Molecular Imprinting on Mn-Doped ZnS Quantum Dots for Room-Temperature Phosphorescence Optosensing of Pentachlorophenol in Water[J]. Anal Chem, 2009, 81(4):1615-1621.
[12]	Chen J L, Gao Y C, Xu Z B, et al.A Novel Fluorescent Array for Mercury(Ⅱ) Ion in Aqueous Solution with Functionalized Cadmium Selenide Nanoclusters[J]. Anal Chim Acta, 2006, 577(1):77-84.
[13]	Ali E M, Zheng Y G, YU H H, et al.Ultrasensitive Pb2+ Detection by Glutathione-Capped Quantum Dots[J]. Anal Chem, 2007, 79(24):9452-9458.
[14]	Lai S J, Chang X J, Fu C. Cadmium Sulfide Quantum Dots Modified by Chitosan as Fluorescence Probe for Copper(Ⅱ)[J]. Microchim Acta, 2009, 165(1/2):39-44.
[15]	Shang Z B, Wang Y, Jin W J. Triethanolamine-capped CdSe Quantum Dots as Fluorescent Sensors for Reciprocal Recognition of Mercury(Ⅱ) and Iodide in Aqueous Solution[J]. Talanta, 2009, 78(2):364-369.
[16]	Jalilehvand F, Mah V, Leung B O, et al.Cadmium(Ⅱ) Cysteine Complexes in the Solid State:A Multispectroscopic Study[J]. Inorg Chem, 2009, 48(9):4219-4230.
[17]	Vairavamurthy M A, Goldenberg W S, Ouyang S, et al.The Interaction of Hydrophilic Thiols with Cadmium: Investigation with a Simple Model, 3-Mercaptopropionic Acid[J]. Mar Chem, 2000, 70(1/3):181-185.
[18]	Trung N N, Luu Q P, Son B T, et al.Enhanced Fluorescence, Morphological and Thermal Properties of CdSe/ZnS Quantum Dots Incorporated in Silicone Resin[J]. Nanosci Nanotechnol, 2013, 13(1):434-442.
[19]	Wang Y, Tang Z Y, Correa-Duarte M A, et al. Mechanism of Strong Luminescence Photoactivation of Citrate-Stabilized Water-Soluble Nanoparticles with CdSe Cores[J]. J Phys Chem B, 2004, 108:15461-15469.
[20]	Liu F C, Cheng T L, Shen C C, et al.Synthesis of Cysteine-Capped ZnxCd1-xSe Alloyed Quantum Dots Emitting in the Blue-Green Spectral Range[J]. Langmuir, 2008, 24:2162-2167.
[21]	Koneswaran M, Narayanaswamy R. l-Cysteine-capped ZnS Quantum Dots Based Fluorescence Sensor for Cu2+ Ion[J]. Sens Actuators B, 2009, 139:104-109.
[22]	Wang G L, Dong Y M, Yang H X, et al.Ultrasensitive Cysteine Sensing Using Citrate-capped CdS Quantum Dots[J]. Talanta, 2011, 83:943-947.
[23]	Costa-Fernández J M, Pereiro R, Sanz-Medel A. The Use of luminescent Quantum Dots for Optical Sensing[J]. Trends Anal Chem, 2006, 25(3):207-218.
[24]	Isarov A V, Chrysochoos J. Optical and Photochemical Properties of Nonstoichiometric Cadmium Sulfide Nanoparticles: Surface Modification with Copper(Ⅱ) Ions[J]. Langmuir, 1997, 13(12):3142-3149.
[25]	Duan J L, Jiang X C, Ni S Q, et al.Facile Synthesis of N-Acetyl-l-cysteine Capped ZnS Quantum Dots as an Eco-friendly Fluorescence Sensor for Hg2+[J]. Talanta, 2011, 85(4):1738-1743.
[26]	Touceda-Varela A, Stevenson E I, Galve-Gasión J, et al.Selective Turn-on Fluorescence Detection of Cyanide in Water Using Hydrophobic CdSe Quantum Dots[J]. Chem Commun, 2008, 44(17):1998-2000.
[27]	Lide D R. Handbook of Chemistry and Physics[M]. Corporate Blvd N W, Boca Raton, 2000:33431.