Shuttle-based fluorogenic silver-cluster biolabels.
Shuttle-based fluorogenic silver-cluster biolabels.
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DOI：
10.1002/anie.200804137
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发表时间：
2009
影响因子：
16.6
通讯作者：
Dickson, Robert M.
中科院分区：
文献类型：
--
作者：
Yu, Junhua;Choi, Sungmoon;Dickson, Robert M.
大多数分子/细胞标记利用通过一般有机/无机化学缀合至生物活性分子的有机染料。虽然有机染料的缺点，如光稳定性差[1]和亮度低[2]限制了可观察到的拷贝数，但缺乏标记的选择性往往更严重地限制了它们在活细胞成像和单分子研究中的应用[3]。特异性可以通过抗体和其他强亲和力对（如抗生物素蛋白-生物素）来解决[4，5]，但直接共价技术在亚pM浓度下至关重要，因为这超出了基于抗体的亲和力的结合极限。遗传编码的荧光蛋白是活细胞中特异性荧光标记的极好解决方案，但不利的有机染料物理不稳定性（闪烁和漂白）仍然存在，加上由于大标记尺寸而引起的潜在扰动[6]。克服有机标记的光不稳定性的尝试已经产生了更亮的量子点标记[7]，但是，在提供优异的信号的同时，这些发射体引入了额外的问题，例如大的物理尺寸、聚集、毒性、多价性和强的荧光不稳定性[8-10]。新出现的基于银簇的标记同时解决了亮度、光稳定性、单价、尺寸和荧光不稳定性的问题，提供了作为分子标记剂的优异潜力[11-15]。光谱纯的发射体已经产生，范围从蓝色到近红外，荧光量子产率（ΦF）高达40%，完全组装的ssDNA封装的SC的流体动力学半径约为2.5 nm [16]。此外，在本体和单分子水平上，SC还显示出优异的亮度和光稳定性[17]。Ag纳米团簇通常在DNA存在下通过Ag盐的直接BH 4 −还原在ss-DNA支架内产生[12]。这种方法可以用来在目标蛋白质上产生高发射性的标记，但BH 4 −是一种相当苛刻的还原剂。为了最大限度地减少暴露，我们研究了其他支架，其中簇可以首先合成，但将使整个簇转移到ss-DNA澄清剂-荧光簇穿梭。确定稳定Ag纳米团簇发射[18]，研究聚（丙烯酸）（PA）作为低ΦF银团簇支架。最初尝试在市售的小线性PA中通过用硼氢化钠还原来产生SC，产生非常低的SC浓度和低ΦF，同时产生银纳米颗粒。当银离子首先与3-（2-氨基乙氨基）丙基三甲氧基硅烷（APTMOS）形成络合物后再进行PA稳定化和硼氢化物还原时，纳米粒子的形成被消除，团簇产率大大提高。复合物的质谱主要显示2：1 APTMOS：Ag+复合物，其可能限制最终Ag簇的大小
Most molecular/cellular labeling utilizes organic dyes conjugated to bioactive molecules through general organic/inorganic chemistry. Though shortcomings of organic dyes such as poor photostability [1] and low brightness [2] limit observable copy numbers, lack of selectivity in labeling often more seriously limits their application in live cell imaging and single molecule studies [3]. Specificity can be addressed through antibodies and other strong affinity pairs such as avidin-biotin [4, 5], but direct covalent technologies are crucial at sub-pM concentrations, as this is beyond the binding limits of antibody-based affinities. Genetically encoded fluorescent proteins are an excellent solution for specific fluorescent labeling in live cells, but disadvantageous organic dye photophysical instabilities (blinking and bleaching) remain, coupled with the potential perturbation due to large label size [6]. Attempts to overcome photoinstabilities of organic labels have produced much brighter quantum dot labels [7], but, while providing excellent signals, these emitters introduce additional problems such as large physical size, aggregation, toxicity, polyvalency, and strong fluorescence intermittency [8–10]. Simultaneously addressing concerns of brightness, photostability, monovalency, size, and fluorescence intermittency, newly emerging silver cluster-based labels offer excellent potential as molecular labeling agents [11–15]. Spectrally-pure emitters have been produced ranging from the blue to the near IR, with fluorescence quantum yields (ΦF) up to 40% and hydrodynamic radii of the fully assembled ssDNA-encapsulated SCs of~ 2.5 nm [16]. Moreover, at bulk and single molecule levels, SCs also show both excellent brightness and photostability [17].Ag nanoclusters are typically created within ss-DNA scaffolds through direct BH4− reduction of Ag salts in the presence of DNA [12]. Such methods can be employed to generate highly emissive labels on proteins of interest, but BH4− is a rather harsh reductant. To minimize exposure, we investigated other scaffolds in which clusters could first be synthesized, but would enable whole cluster transfer to the ss-DNA encapsulant–a fluorogenic cluster shuttle. Identified to stabilize Ag nanocluster emission [18], poly (acrylic acid)(PA) was investigated as a low ΦF silver cluster scaffold. Initial attempts at SC creation within a commerciallyavailable, small linear PA by reduction with sodium borohydride yielded both very low SC concentrations and low ΦF’s, with simultaneous generation of silver nanoparticles. Nanoparticle formation was eliminated and cluster yield greatly improved when silver ions first formed complexes with 3-(2-aminoethylamino) propyltrimethoxy silane (APTMOS) before PA stabilization and borohydride reduction. Mass spectrometry of the complexes predominantly shows 2: 1 APTMOS: Ag+ complexes which likely limit final Ag cluster size
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影响因子：
15
作者：
Liu, Wenhao;Howarth, Mark;Bawendi, Moungi G.
通讯作者：
Bawendi, Moungi G.
DOI：
10.1073/pnas.0610677104
发表时间：
2007-07-31
影响因子：
11.1
作者：
Vosch, Tom;Antoku, Yasuko;Dickson, Robert M.
通讯作者：
Dickson, Robert M.
影响因子：
3.2
作者：
RONNOVJESSEN, L;CELIS, JE;PETERSEN, OW
通讯作者：
PETERSEN, OW
影响因子：
29.4
作者：
Shen, Zhong;Duan, Hongwei;Frey, Holger
通讯作者：
Frey, Holger
影响因子：
56.9
作者：
Chan, WCW;Nie, SM
通讯作者：
Nie, SM