Zhang Ning, Liu Yuanyuan, Tong Lili, Xu Kehua, Zhuo Linhai, Tang Bo
College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Shandong Normal University, Jinan, PR China.
Analyst. 2008 Sep;133(9):1176-81. doi: 10.1039/b803226b. Epub 2008 Jun 19.
A novel assembly of Au NPs-beta-CDs-FL for the fluorescent probing of cholesterol (Cho) is provided. Gold nanoparticles (Au NPs) possessing a high extinction coefficient function can be used as excellent fluorescent quenchers in Au NP-fluorophore composites. Inclusion of fluorescein (FL) into beta-cyclodextrin (beta-CD) makes fluorescence resonance energy transfer (FRET) occur through the donor and quencher nearby. FRET switches off because of the cholesterol-induced release of FL from beta-CD cavity, which results in the fluorescence recovery of the quenched dye. Spectral analysis supported the idea that the signal enhancement was attributed to the formation of an inclusion complex of the cholesterol moiety in beta-CD, resulting in separation of FL from the Au NPs. This phenomenon is explained by the guest-induced location change of the FL from inside to outside the cavity, suggesting that the assembly of Au NPs-beta-CDs-FL is effective as a fluorescent probe for cholesterol recognition. The fluorescence increase is proportional to the concentration of cholesterol in the range of approx. 30 nM to 15 muM. A concentration of cholesterol as low as 9 nM would be readily detected. The precision of the method applied to the determination of quantities of cholesterol present in human blood serum were satisfactory.
本文提供了一种用于荧光探测胆固醇（Cho）的新型金纳米颗粒- β-环糊精-荧光素（Au NPs-β-CDs-FL）组装体。具有高消光系数功能的金纳米颗粒（Au NPs）在Au NP-荧光团复合材料中可用作优异的荧光猝灭剂。将荧光素（FL）包合到β-环糊精（β-CD）中会使荧光共振能量转移（FRET）通过附近的供体和猝灭剂发生。由于胆固醇诱导FL从β-CD腔中释放，FRET关闭，这导致猝灭染料的荧光恢复。光谱分析支持这样的观点，即信号增强归因于β-CD中胆固醇部分形成包合物，导致FL与Au NPs分离。这种现象可以通过客体诱导的FL从腔内到腔外的位置变化来解释，这表明Au NPs-β-CDs-FL组装体作为胆固醇识别的荧光探针是有效的。荧光增加与约30 nM至15 μM范围内的胆固醇浓度成正比。低至9 nM的胆固醇浓度也能很容易地被检测到。应用该方法测定人血清中胆固醇含量的精密度令人满意。
