基于上转换荧光共振能量转移的Hg~(2+)侧流检测模型的设计和应用

本工作利用荧光共振能量转移(FRET)过程,以上转换荧光纳米材料(UCNPs)作为能量供体,以金纳米粒子(AuNPs)作为能量受体,通过适配体识别Hg~(2+),在硝化纤维素膜(NC)上制备侧流检测试纸条。Hg2+的参与会拉近能量供受体距离,引起检测区UCNPs的荧光猝灭。通过检测区的荧光猝灭效率,可判断样品中的Hg~(2+)浓度。该传感器在缓冲溶液中的检测线性范围为0.1~100nmol/L;检出限为0.1nmol/L。本研究成功证实了上转换荧光共振能量转移体系在侧流模型应用的可行性。     

一个高度灵敏和高选择性铝离子比率探针的合成及应用

本文构建了一种基于3-苯丙噻唑基-2-羟基-5-甲基苯甲醛的荧光探针用于检测铝离子。该荧光探针能够灵敏、高选择性地检测铝离子,并显示出颜色和强烈的荧光变化双重响应。研究结果表明,该探针对铝离子表现出非常好的荧光增强效果,检测过程中其它金属离子不会对检测结果产生明显的干扰。其比率荧光强度(I490/I567)与铝离子的浓度(0~20μmol/L)之间具有良好的线性关系,检测限低至0.5μmol/L。由于具有高效的选择性,该探针可以用于检测污染河水中的铝离子含量。     

高荧光量子产率钕、氮双掺杂碳点用于柳氮磺吡啶检测及Hela细胞成像

以柠檬酸氢二铵、缓血酸铵和硝酸钕为起始原料,通过水热法合成了荧光量子产率为93.05%、发蓝色荧光的钕、氮双掺杂碳点（Nd,N-CDs）。采用透射电子显微镜（TEM）、粉末X射线衍射（XRD）、红外光谱（FT-IR）及X射线光电子能谱（XPS）等技术对Nd,N-CDs的形貌及表面结构进行了详细表征,采用紫外可见吸收光谱及荧光光谱考察了其光学性质和稳定性。结果显示,药物分子柳氮磺吡啶（SSZ）能够使Nd,N-CDs的荧光显著降低,而金属离子及另外4种药物分子没有明显效果。由此,建立了一种选择性检测SSZ的荧光检测方法,线性检测范围在0.1~50 μmol/L之间,检出限低至0.05 μmol/L。机理探讨表明,荧光猝灭主要涉及动态猝灭和荧光共振能量转移两种机制。所建立的分析方法能用于测定实际药片中的SSZ含量,回收率为98.1%~104.2%。此外,Nd,N-CDs表现出很好的生物相容性,能够作为荧光探针穿透细胞壁使细胞质染色,因不会进一步穿透进入细胞核,很好的避免了对细胞的深层次破坏。     

d-Proline capped gold nanoclusters for turn-on detection of serum Raltitrexed

With d-proline as the reducing and capping agent, fluorescent gold nanoclusters were rapidly prepared (d-Pro@AuNCs) within 10 min at 100 °C. In the present of gold nanoparticles, the fluorescence of d-Pro@AuNCs was remarkably quenched. Interestingly, based on the electrostatic interaction between anticancer drug Raltitrexed and gold nanoparticles induced fluorescence “turn-on” principle, a high selective assay for detection of Raltitrexed was established with the probe associating the fluorescence emission at 435 nm. The fluorescence intensity of d-Pro@AuNCs linearly correlated with the concentration of Raltitrexed in the range from 5.0 μmol/L to 40.0 μmol/L (R² = 0.999) and the limit of detection was 1.9 μmol/L. Further, after Raltitrexed was abdominal injected in rats, a metabolic approach was constructed with the prepared fluorescent probe. It showed great potential of AuNCs-based sensing probes for application in analysis of serum anticancer drugs.     

高效液相色谱荧光检测法同时检测鸡肉中甲砜霉素、氟苯尼考及氟苯尼考胺残留

建立了高效液相色谱荧光法同时检测鸡肉中甲砜霉素、氟苯尼考和氟苯尼考胺残留的新方法。样品经丙酮、二氯甲烷提取,饱和正己烷脱脂,氮吹仪吹干浓缩后,以乙腈-NaH2PO4溶液(0.01 mol/L,含0.005 mol/L十二烷基硫酸钠和0.1％三乙胺)(体积比32：68)为流动相,流速为1.0 mL/min,荧光检测激发波...     

高灵敏检测葡萄糖的新型荧光纳米传感器

构建了一种用于高灵敏检测葡萄糖的新型荧光纳米传感器.在辣根过氧化物酶(HRP)的催化下,H2O2氧化3,3′,5,5′-四甲基联苯胺(TMB),生成具有强吸光性质的TMB多聚体,导致1-氧-1H-非那烯-2,3-二腈(1-Oxo-1H-phenalene-2,3-dicarbonitrile, OPD)分子的荧光发生淬灭,基于此实现H2O2的定量检测,线性范围分别为0.05~0.80 μmol/L和1~10 μmol/L,检出限(3σ)为0.02 μmol/L.由于葡萄糖氧化酶(Gox)可催化葡萄糖分解产生H2O2,基于此可以实现葡萄糖分子的定量检测,线性范围分别为0.1~3.0 μmol/L和4.0~30 μmol/L, 检出限(3σ)为0.02 μmol/L.将本方法用于实际血清样品中葡萄糖的定量检测,结果与临床检测结果相符.     

Upconversion nanoparticle-based fluorescence resonance energy transfer assay for Cr(III) ions in urine

A novel assay of chromium(III) ion based on upconversion fluorescence resonance energy transfer was designed and established. Lysine-capped NaYF₄:Yb/Er upconversion nanoparticles (UCNPs) and dimercaptosuccinic acid-capped gold nanoparticles (AuNPs) were used as the energy donor and acceptor, respectively. They were bound together via electrostatic interaction, resulting in the quenching of the fluorescence of UCNPs by AuNPs. Chromium(III) ions can specifically and strongly interact with dimercaptosuccinic acid that was modified on the surface of AuNPs, leading to the separation of AuNPs from UCNPs and the recovery of fluorescence of UCNPs. The fluorescence recovery of UCNPs showed a good linear response to Cr³⁺ concentration in the range of 2–500 nM with a detection limit of 0.8 nM. This method was further applied to determine the levels of Cr³⁺ in urine. Compared with other fluorescence methods, current method displayed very high sensitivity and signal-to-noise ratio because of the excitation of near-infrared that can eliminate autofluorescence, providing a promising examination of biological samples for the diagnostic purposes.     

一锅法合成聚乙烯吡咯烷酮修饰的铜纳米团簇用于槲皮素的检测

作为检测槲皮素的有效途径,在荧光法中如何通过简单的方法合成性能优良的荧光探针具有重要的意义。 本文以聚乙烯吡咯烷酮(PVP)为保护剂,抗坏血酸为还原剂,化学还原法合成PVP保护的分散性好、稳定性高、强荧光的铜纳米团簇(PVP-Cu NCs)。 样品表现出良好的水溶性,光稳定性和强离子稳定性。 通过紫外可见光谱(UV-Vis)、分子荧光光谱、透射电子显微镜(TEM)和X射线光电子能谱分析(XPS)对铜纳米团簇的光学性质和结构进行了分析。 结果表明:该铜纳米团簇的最大激发和发射波长分别为366和429 nm,平均粒径大小为2 nm。 基于槲皮素对该铜纳米团簇的猝灭作用,构建了一种可用于检测槲皮素的荧光传感器。 该传感体系检测槲皮素的线性范围为0.1～0.9 μmol/L和15～60 μmol/L,检测限为0.053 μmol/L(S/N=3)。 该传感器对槲皮素的检测具有很高的灵敏度和良好的选择性,可用于实际样品中槲皮素的检测。     

一种检测水合肼荧光探针的合成与应用

基于香豆素类染料,设计合成了一种具有较高选择性和灵敏度,可在生理条件(pH 7.4)下检测水合肼的荧光探针,同时利用核磁共振和高分辨质谱对探针的分子结构进行了表征。基于水合肼进攻探针分子结构中的4-丁酸酯,生成酚氧负离子,同时发生分子内环化反应后生成具有强烈荧光的亚胺香豆素,实现了探针分子对水合肼的检测。光谱学研究表明,当向探针溶液加入水合肼(0~100μmol/L)后,探针溶液在绿色光谱区域(502 nm)呈现一个显著的荧光增强响应(增强至55倍)。并且,探针可以检测相对较低浓度的水合肼,检出限为1.7×10~(-7)mol/L。此外,相对于其他阴离子和亲核试剂,探针对水合肼的识别显示出较高的选择性和灵敏度。探针成功实现了细胞内水合肼的荧光成像,证明其在细胞成像中具有潜在的应用能力。     

镝荧光探针的构建及对牛奶中四环素残留的检测

在乙醇体系中构建三元配合物的镝荧光探针,并利用盐酸四环素(TC)对镝荧光探针具有荧光猝灭作用,提出了一种检测牛奶中四环素残留的新方法.首先确定体系的激发波长为305 nm,发射波长为574 nm.在配比、加料顺序、时间等方面对镝荧光探针进行了条件优化,确定了镝离子(Dy³⁺)、磺基水杨酸(SSA)、三正辛基氧化磷(TOPO)的最佳配比为1:2:0.1和30 min最佳检测时间.其次建立了检测盐酸四环素的线性曲线,并获得检测范围为10^-6~2×10^-5 mol/L.最后,利用此荧光探针对处理的牛奶样品进行加样回收检测,回收率在96.9 %~104.4 %.实验证明建立的方法科学可行,对盐酸四环素具有高选择性.     

用于检测Al3+和pH值的双功能荧光分子探针

利用荧光素(Fluorescein)对罗丹明6G(Rhodamine 6G)进行修饰,得到荧光分子探针R6G-Flu杂化物.此探针可特异性识别Al3+,检出限可低至10-8 mol/L级;向含有探针分子的溶液中加入Al3+后,溶液的颜色由无色变为粉色,并且在紫外灯下发出绿色荧光,可实现肉眼对10 μmol/L Al3+的定性检测.考察了不同pH值下R6G-Flu的荧光性质. 结果表明,此探针还可用于酸性范围(pH 3.00~6.00)和碱性范围(pH 8.00~10.50)内pH值的精确检测.实验结果表明,R6G-Flu是一种可用于Al3+和pH值检测的双功能荧光分子探针.     

纳米金信号探针/石墨烯修饰免疫传感器检测微囊藻毒素

利用石墨烯纳米片层(GS)偶联牛血清白蛋白(BSA)标记的微囊藻毒素(MCLR)(BSA-MCLR)构建了纳米金(Au NPs)为信号探针的电流型免疫传感器。分别用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和紫外-可见吸收光谱对合成纳米材料进行表征;用循环伏安法研究修饰电极表面的电化学特性。通过待测MCLR与固定的BSA-MCLR竞争结合抗体(anti-MCLR),之后恒电位将Au NPs氧化为Au Cl-4,再利用差分脉冲伏安法(DPV)进行阴极电位扫描,还原Au Cl-4为Au,以产生的峰电流值为检测信号,测定MCLR浓度。最佳实验条件下,用免疫传感器测定MCLR的线性范围为0.1~50μg/L,检出限为0.05μg/L。对传感器的重现性、稳定性和选择性进行了考察。相较于酶标探针,以Au NPs为信号探针标记抗体,可使检测过程更经济便捷,稳定性更强,检测效果良好。     

基于芬顿反应和硫磺素T构建免标记荧光传感器用于葡萄糖的检测

基于芬顿反应和硫磺素T(ThT)构建新奇的免标记荧光传感器用于葡萄糖的检测。当无葡萄糖存在时,ThT诱导富G-DNA探针形成G-四链体/ThT复合物,ThT的荧光强度显著增强;当葡萄糖存在时,葡萄糖氧化酶催化葡萄糖产生H2 O2,在Fe^2+催化的芬顿反应作用下,H2 O2转化为羟基自由基(·OH),·OH引发DNA的氧化损伤导致富G-DNA探针裂解为短寡核苷酸片段而丧失形成G-四链体/ThT的能力,ThT的荧光强度显著降低,从而实现对葡萄糖的检测。在优化的检测条件下,G-四链体/ThT荧光强度变化和葡萄糖浓度在0.5~45μmol/L的范围内呈现较好的线性关系(R^2=0.99268),检出限为0.1μmol/L。利用本法对葡萄糖加标的血液样品进行分析,葡萄糖的回收率为90.7%~118.3%,相对标准偏差为1.7%~5.8%,方法可用于血糖检测。     

基于对荧光铜纳米簇合成的抑制检测三聚氰胺

三聚氰胺能与铜离子(Cu2+)形成配合物,对荧光铜纳米簇的合成有明显抑制作用,且其抑制程度与三聚氰胺浓度在一定范围内呈线性关系.基于此构建了一种简单、快速检测三聚氰胺的方法.以聚T单链DNA为模板合成的铜纳米簇作为荧光探针,当三聚氰胺存在时,Cu2+与三聚氰胺生成配合物,阻碍铜纳米簇的合成,导致荧光强度降低.在优化的实验条件下,三聚氰胺浓度在5~120 μmol/L范围内呈良好的线性关系,检出限为1.5 μmol/L,牛奶样品中三聚氰胺加标回收率为96.3%~104.4%.与传统纳米金/银、量子点等方法相比,本方法具有简单、快速、灵敏等优点.     

金纳米颗粒等离子体共振吸收光谱检测头孢唑啉

根据金纳米粒子等离子体共振吸收引起的溶液颜色变化,建立了一种快速、简便检测头孢唑啉的色度分析方法.方法线性范围为0.1～5.0 μmol/L,检测限为14 nmol/L.将该方法用于头孢唑啉钠粉针剂的分析,回收率在97.4％～100.2％之间,相对标准偏差小于6.1％.     

基于氮掺杂碳点的荧光增强简便、快速而准确地检测环丙沙星

以苹果酸为碳源,磷酸铵提供氮源,采用固态热解法一步合成一种水溶性的、氮掺杂的蓝色荧光碳点(N-CDs)。 所得到的碳点荧光量子产率高达20.7%,形貌近似球形,平均粒径约为3.3 nm。 基于环丙沙星(CIP)对碳点的荧光增强作用,建立了一种CIP的定量检测方法。 最佳实验参数为:碳点浓度为7.5 μg/mL,pH值为5.9,孵化时间为5 min。 在此实验条件下,碳点的荧光强度增加值(ΔF)和CIP的浓度在0.39~40.00 μmol/L范围内呈良好的线性关系,方法的检出限为0.12 μmol/L,相对标准偏差(n=5)为4.2%。 干扰实验结果指出,除了铜离子具有明显的影响外,其它共存物质的干扰可以忽略不计,而铜离子的干扰可通过加入草酸铵来掩蔽。 最后利用所构建的荧光传感器对实际样品中CIP进行检测,回收率在93%~107%之间。 本研究为CIP定量分析提供了一种简单、快速、灵敏度高、选择性好而有效的测定方法。     

Ethylenediaminetetraacetic Acid Functionalized Gold Nanoparticles for Sensitive Colorimetric Detection of Chromium(III)

A cost‐effective and sensitive colorimetric method was described for the determination of chromium(III) ion (Cr³⁺) by using ethylenediaminetetraacetic acid functionalized gold nanoparticles (EDTA‐AuNPs) as a probe. The stable and dispersed EDTA‐AuNPs were prepared by reducing HAuCl4 with sodium borohydride in presence of EDTA as a capping agent. Upon the addition of Cr³⁺, the colour of EDTA‐AuNPs solution changed from red to violet, which was in response to the surface plasmon absorption of dispersed and aggregated EDTA‐AuNPs. The procedure allowed the determination of Cr³⁺ in the range of 0.1–1.0 mol/L. The limit of detection for Cr³⁺ was 0.08 mol/L. The relative standard deviation was 2.5 % for eight repeated measurements of 0.6 mol/L Cr³⁺ solution. The method was applied to the determination of Cr³⁺ in water samples.     

High selective determination iron(II) by its enhancement effect on the fluorescence of pyrene-tetramethylpiperidinyl (TEMPO) as a spin fluorescence probe

A novel fluorescence method determination for iron(II) with a high selectivity and sensitivity has been proposed, based on the enhancement of fluorescence signals resulting from specific redox reaction between synthesized spin fluorescence probe pyrene-tetramethylpiperidinyl (TEMPO) and iron(II). Under the experimental conditions, fluorescent probe displayed a rapid and linear response for iron(II) over the concentration range from 2.4 x 10(-7) to 3.6 x 10(-6) mol/L. The limit of detection was 4.0 x 10(-8) mol/L. The relative standard deviation of six replicate measurements was 1.90% for 3.0 x 10(-7) mol/L iron(II). Because of the specific redox reaction between developed spin fluorescence probe and iron(II), there are few interference by other ions, especially in the presence of relative high concentration iron(III). The method has been successfully applied for iron(II) determinations in two different kinds of real samples. Results determined by the proposed method agree favorably with those determined UV-vis spectrometry method with 1,10-phenanthroline.     

金纳米粒子比色探针检测牛奶及鸡蛋中的三聚氰胺

三聚氰胺能诱导金纳米粒子(AuNPs)团聚,溶液颜色由酒红色变为紫色或蓝灰色.以AuNPs作为比色探针,建立了快速检测牛奶和鸡蛋中三聚氰胺的方法.实验优化得最佳反应条件为:AuNPs粒径13 min、pH=7、反应时间10 min和温度为室温.对样品中常见物质进行了干扰实验.样品经10％三氯乙酸和氯仿提取、离心分离后可...     

Aptamer-wrapped gold nanoparticles for the colorimetric detection of omethoate

Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.