Nile red-adsorbed gold nanoparticles for selective determination of thiols based on energy transfer and aggregation
Nile red-adsorbed gold nanoparticles for selective determination of thiols based on energy transfer and aggregation
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DOI：
10.1021/ac049787s
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发表时间：
2004-07-01
影响因子：
7.4
通讯作者：
Chang, HT
中科院分区：
文献类型：
--
作者：
Chen, SJ;Chang, HT
第一次，一种32纳米金纳米粒子（GNPs）的水溶液被尼罗红（NR）非共价吸附，用于检测硫醇。由于NR和GNPs之间的荧光共振能量转移，制备的NRGNPs荧光弱。在pH值为4.0时，含有NRGNPs的溶液的荧光随着硫醇的加入而增加，但当添加胺、酸、醇、牛血清白蛋白或血红蛋白时则没有。这种现象允许选择性测定巯基如半胱胺和同型半胱氨酸，其检测限分别为10.2 nM和10.9 nM，信噪比为3。有趣的是，我们发现在硫醇存在下从GNPs中解吸的物质的激发（lambda(ex) = 480 nm），发射（lambda(em) = 610 nm）和质谱（m/z 282）与NR （lambda(ex) = 580 nm）不同；λ (em) = 652 nm；M /z 318)，表示新产品形成。当同时进行荧光和比色测定时，该方法的选择性进一步提高，因为在pH 4.0时，NRGNPs的颜色在带负电荷的硫醇（例如，N-（2-巯基丙酰）甘氨酸）存在时不会改变，但在中性硫醇（例如，3-巯基-1,2-丙二醇）和带正电荷的硫醇（例如，半胱胺）存在时，由于聚集，分别从栗色变为紫色和薰衣草色。这一特点使得硫醇的种类可以分别在浓度>1.0和0.1 muM下通过肉眼和紫外-可见吸收测定。根据NRGNP颜色变化的速率，还原型谷胱甘肽（慢）很容易与氧化型谷胱甘肽（无聚集和位移）以及半胱氨酸和同型半胱氨酸（快）区分。
For the first time, an aqueous solution of 32-nm gold nanoparticles (GNPs), to which Nile red (NR) has been noncovalently adsorbed, has been used for sensing thiols. The as-prepared NRGNPs fluoresce weakly as a result of fluorescence resonance energy transfer between NR and the GNPs. The fluorescence of a solution containing NRGNPs at pH 4.0 increases upon the addition of thiols, but not when amines, acids, alcohols, bovine serum albumin, or hemoglobin are added. This phenomenon allows for the selective determination of thiols such as cysteamine and homocysteine, which have limits of detection of 10.2 and 10.9 nM, respectively, at a signal-to-noise ratio of 3. Interestingly, we have found that the excitation (lambda(ex) = 480 nm), emission (lambda(em) = 610 nm), and mass spectra (m/z 282) of the substance that desorbs from the GNPs in the presence of thiols are different from those of NR (lambda(ex) = 580 nm; lambda(em) = 652 nm; m/z 318), which indicates that a new product forms. When simultaneously conducting fluorescence and colorimetric assays, the selectivity of this approach further improves because at pH 4.0, the color of the NRGNPs does not change in the presence of negatively charged thiols, (e.g., N-(2-mercaptopropionyl)glycine), but changes from maroon to purple and lavender in the presence of neutral thiols (e.g., 3-mercapto-1,2-propanediol) and positively charged thiols (e.g., cysteamine), respectively, as a result of aggregation. This feature allows the types of thiols to be determined at concentrations >1.0 and 0.1 muM by the naked eye and by UV-vis absorption, respectively. Depending on the rate at which the NRGNP color changes, reduced glutathione (slow) is readily distinguishable from oxidized glutathione (no aggregation and no displacement) and from cysteine and homocysteine (fast).