Simple and sensitive determination of papain by resonance light-scattering with CdSe quantum dots.
Simple and sensitive determination of papain by resonance light-scattering with CdSe quantum dots.
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DOI：
10.1016/j.colsurfb.2012.07.026
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发表时间：
2013-02
期刊：
影响因子：
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通讯作者：
Sha Huang;Qi Xiao;Wei Su;Peiyuan Li;Jianqiang Ma;Zhike He
中科院分区：
文献类型：
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作者：
Sha Huang;Qi Xiao;Wei Su;Peiyuan Li;Jianqiang Ma;Zhike He
基于巯基乙酸封端的CdSe量子点（MAA-QDs）在水溶液中的共振光散射（RLS）强度增量，建立了一种简单、灵敏的木瓜蛋白酶检测方法。同时，对共振光散射特性和最佳条件进行了详细研究。在优化条件下，MAA-QDs共振光散射强度与木瓜蛋白酶浓度的线性范围为1.0×10− 8 M ~ 6.0×10− 7 M，相关系数（R2）为0.9977，检测限（3σ black）为5.1×10− 9 M。相对标准偏差（R.S.D.）对1.6×10 - 7 M木瓜蛋白酶的回收率为1.0%（n=5）。常见离子、蛋白质和20种氨基酸等共存杂质几乎不干扰。该方法具有简便、快速、灵敏等优点。用该方法对三个合成样品进行了分析，结果令人满意。通过目视法、透射电镜和时间分辨荧光光谱等方法系统研究了MAA-QDs与木瓜蛋白酶的相互作用，结果表明MAA-QDs与木瓜蛋白酶之间的相互作用主要是静电作用。
In this contribution, a simple and sensitive method for papain detection was established based on the increment of the resonance light-scattering (RLS) intensity of mercaptoacetic acid-capped CdSe quantum dots (MAA-QDs) in aqueous solution. Meanwhile, the RLS characteristics and the optimal conditions were investigated in detail. Under the optimized conditions, the linear range of MAA-QDs RLS intensity versus the concentration of papain was 1.0×10−8M to 6.0×10−7M, with a correlation coefficient (R2) of 0.9977 and a limit of detection (3σ black) of 5.1×10−9M. The relative standard deviation (R.S.D.) for 1.6×10−7M papain was 1.0% (n=5). There was almost no interference to coexisting foreign substances including common ions, proteins and 20 amino acids. The proposed method possessed the advantages of simplicity, rapidity and sensitivity. Three synthetic samples were analyzed by the methodology and the results were satisfying. The interaction between MAA-QDs and papain was also investigated systematically by using visual method, transmission electron microscopy and time-resolved fluorescence spectra, and the results indicated that the main force between MAA-QDs and papain was electrostatic interaction.