Fluorescent turn-on detection of cysteine using a molecularly imprinted polyacrylate linked to allylthiol-capped CdTe quantum dots
Fluorescent turn-on detection of cysteine using a molecularly imprinted polyacrylate linked to allylthiol-capped CdTe quantum dots
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DOI：
10.1007/s00604-014-1209-6
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发表时间：
2014-03
影响因子：
5.7
通讯作者：
M. Chao;Chiung-Wen Hu;Jian-Lian Chen
中科院分区：
文献类型：
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作者：
M. Chao;Chiung-Wen Hu;Jian-Lian Chen
用巯基乙酸（TGA）封端的CdTe量子点如果暴露于半胱氨酸（Cys）溶液中则显示出强的开启荧光响应。为了利用这种效应，半胱氨酸的分子印迹聚合物（MIP）通过烯丙基甲基共价连接到量子点。所得的纳米材料（量子点，MIP涂层量子点，和nonimprint-coated量子点），其特征在于通过FTIR和扫描电子显微镜。在磷酸盐缓冲溶液中研究了半胱氨酸的吸附（pH 7.4）相对于平衡时间（分别为5、15和40 min）、结合常数[2.98、2.42和0.96（× 104 M −1）]和Langmuir等温线（R2= 0.9995、0.9999和0.9983），Cys浓度范围为3.33 μM至500 μM。方法的检出限为0.85 μM（3σ，空白，n = 10）。MIP涂覆的QD对Cys超过19种其他氨基酸的选择性与裸QD的选择性相似，但是当与裸（非印迹）QD获得的回收率（135%和120%）相比时，MIP-QD分别从还含有牛血清白蛋白（90%）和胎牛血清（97%）的溶液中提供更好的Cys回收率。这可能是由于MIP的外壳大大减少了蛋白质包裹、点聚集和基质包含的事实。图使用半胱氨酸模板的开启荧光检测，在一锅聚合中合成了通过烯丙基取代与MIP缀合的量子点（QD），并且与裸QD和非印迹聚合物-QD相比，在血清基质存在下表现出更高的结合选择性。
CdTe quantum dots capped with thioglycolic acid (TGA) display a strong turn-on fluorescence response if exposed to solutions of cysteine (Cys). In order to exploit this effect, a molecularly imprinted polymer (MIP) for Cys was covalently linked to the QDs via allyl mercaptan. The resulting nanomaterials (QDs, MIP-coated QDs, and nonimprint-coated QDs) were characterized by FTIR and scanning electron microscopy. The adsorption of Cys was studied in phosphate buffer (pH 7.4) with respect to equilibration times (5, 15, and 40 min, respectively), binding constants [2.98, 2.42, and 0.96 (×104M−1)], and Langmuir isotherms (R2= 0.9995, 0.9999, and 0.9983) in the Cys concentration range between 3.33 μM to 500 μM. The method has a detection limit of 0.85 μM (3σ, blank, forn= 10). The selectivity of the MIP-coated QDs for Cys over 19 other amino acids is similar to that of bare QDs, but MIP-QDs afford better recoveries of Cys from solutions also containing bovine serum albumin (90 %) and fetal bovine serum (97 %), respectively, when compared to the recoveries that are obtained with bare (non-imprinted) QDs (135 % and 120 %). This is probably due to the fact that the outer MIP shell largely reduces protein wrapping, dot aggregation, and matrix inclusion.FigureUsing the turn-on fluorescence detection of cysteine template, quantum dots (QDs) conjugated with MIP via allyl mercaptan were synthesized in a one-pot polymerization and exhibited a higher binding selectivity in the presence of serum matrices compared to bare QDs and non-imprinted polymer-QDs.