核壳型量子点-纳米金颗粒组装体高效检测神经性毒剂模拟剂

doi:10.15541/jim20180486

摘要/Abstract

摘要：

实验设计制备了一种由12层硫化锌包覆硒化镉的核壳型量子点(CdSe/12ZnS QDs)和纳米金颗粒(Au NPs)自组装形成的CdSe/12ZnS QDs/Au NPs复合结构, 并将其应用于神经性毒剂模拟剂氰基磷酸二乙酯(Diethyl Cyanophosphonate, DCNP)的高效检测。QDs由于与Au NPs存在荧光共振能量转移作用(Fluorescence Resonance Energy Transfer, FRET)而发生荧光猝灭, 乙酰胆碱酯酶(AChE)水解氯化硫代乙酰胆碱(ATC)生成的硫胆碱能够将量子点取代而使量子点荧光恢复。当QDs与Au NPs的摩尔浓度比为20 : 1时, QDs荧光猝灭效果最佳, AChE浓度为1.0×10 ^-3 U/L时, QDs荧光恢复效果最好。DCNP的存在会抑制AChE的活性, 减少硫胆碱的生成并降低QDs的荧光恢复效率, 通过对QDs荧光恢复效率测定能够检测DCNP。在最优条件下对DCNP的检测结果表明, 量子点的荧光恢复效率与DCNP浓度的对数在5.0×10 ^-9~5.0×10 ^-4mol/L的范围内存在良好的线性关系, 检出限达5.0×10 ^-9mol/L。

关键词: 量子点, 纳米金颗粒, 神经性毒剂模拟剂, 荧光共振能量转移

Abstract:

A novel assembly of CdSe/12ZnS core/shell quantum dots (CdSe/12ZnS QDs) and gold nanoparticles (Au NPs) was constructed for highly sensitive detection of nerve agent mimic diethyl cyanophosphonate (DCNP). Due to fluorescence resonance energy transfer (FRET) from CdSe/12ZnS QDs to Au NPs, the emission intensity of QDs was quenched. Thiocholine generated in situ from acetylcholinesterase (AChE) and acetylthiocholine (ATC) would destroy the assembly structure to recover the emission of QDs. However, diethyl cyanophosphonate (DCNP) could inhibit the activity of AChE, thus leading to the suppressed fluorescence recovery. Therefore, the detection of DCNP was achieved by evaluating fluorescence recovery efficiency of QDs. Optimally, a linear relationship between fluorescence recovery efficiency of QDs and logarithmic concentration of DCNP was observed in a range of 5.0×10 ^-9 mol/L to 5.0×10 ^-4 mol/L. As a result, the limit of detection (LOD) was deternimed to be as low as 5.0×10 ^-9 mol/L.

Key words: quantum dots, gold nanoparticles, nerve agents mimic, fluorescence resonance energy transfer

中图分类号:

TN304

李盛菘, 郑永超, 孟澍临, 吴骊珠, 钟近艺, 赵冲林. 核壳型量子点-纳米金颗粒组装体高效检测神经性毒剂模拟剂[J]. 无机材料学报, 2019, 34(8): 893-898.

LI Sheng-Song, ZHENG Yong-Chao, MENG Shu-Lin, WU Li-Zhu, ZHONG Jin- Yi, ZHAO Chong-Lin. Core/Shell Quantum Dots and Au Nanoparticles Assembly for Effective Detection of Nerve Agent Mimic[J]. Journal of Inorganic Materials, 2019, 34(8): 893-898.

图/表 7

图1 QDs/Au NPs组装体形成过程示意图

Fig. 1 Illustration of the construction of QDs/Au NPs assembly

图2 (a) Au NPs、(b) QDs和(c) Au NP/QDs复合物的TEM照片; (d) Au NP/QDs组装体的HRTEM照片

Fig. 2 TEM images of (a) Au NPs, (b) QDs and Au NP/QDs assembly, and (d) HRTEM image of Au NP/QDs assembly

图3 (a) Au NPs 的吸收光谱和CdSe/12ZnS QDs的发射光谱(λex = 400 nm), 内插图为CdSe QDs与Au NPs复合结构在加入AChE和ATC前(黑线)后(红线)荧光强度对比; (b)不同体系的发射光谱, QDs、Au NPs、ATC、AChE和DCNP浓度分别为70 nmol/L、3.5 nmol/L、0.05 mmol/L、1.0×10-3 U/L、5.0×10-6 mol/L

Fig. 3 (a) UV-Vis absorption spectrum of Au NPs and emission spectrum of CdSe/12ZnS QDs excited at 400 nm. The inset is the emission spectra of CdSe QDs/Au NPs complex before (black) and after (red) addition of AChE and ATC; (b) Emission spectra of different systems. The concentration of QDs, Au NPs, ATC, AchE, and DCNP are 70 nmol/L, 3.5 nmol/L, 0.05 mmol/L, 1.0×10-3 U/L and 5.0×10-6 mol/L, respectively

图4 (a)不同Au NPs (7 nmol/L)与QDs配比组装前后荧光对比; (b)不同Au NPs与QDs配比荧光猝灭效率(FQ/FQ0)

Fig. 4 (a) Emission intensity of QDs before and after forming assembly and (b) quenching efficiency (FQ/FQ0) with different Au NPs (7 nmol/L) to QDs ratio

图5 不同AChE浓度下体系的荧光恢复效果

Fig. 5 Fluorescence recovery of the system in the presence of AChE (1.0×10-7~1.0×10-1 U/L)

图6 (a)不同DCNP浓度下(5.0×10-9~5.0×10-4 mol/L)体系荧光发射光谱(λex=400 nm), 内插图为相应的溶液照片; (b)不同DCNP浓度下的体系FR/FR0值, 内插图为FR/FR0与DCNP浓度对数的线性关系

Fig. 6 (a) Emission spectroscopy of system in presence of different concentrations of DCNP (5.0×10-9~5.0×10-4 mol/L) with inset showing the corresponding picture of solutions (DCNP increase from left to right); (b) FR/FR0 varied as a function of concentration of DCNP with inset showing the linear calibration of FR/FR0 on the logarithmic concentration of DCNP

图7 不同干扰物对体系检测DCNP的影响, 其中DCNP和干扰物浓度均为5×10-4 mol/L

Fig. 7 Fluorescence recovery of the system in the presence of DCNP (5×10-4 mol/L) premixed with different disruptors (5×10-4 mol/L)

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