Gao Xue, Li Dan, Tong Ying, Ge Dan, Tang Yiwei, Zhang Defu, Li Jianrong
College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
Luminescence. 2015 Dec;30(8):1389-94. doi: 10.1002/bio.2911. Epub 2015 Apr 10.
A highly sensitive fluorescence method for glycoprotein detection has been established based on fluorescence resonance energy transfer (FRET) between CuInS2 quantum dots (QDs) and rhodamine B (RB). Lectins comprise a group of proteins with unique affinities toward carbohydrate structures, so the process of FRET can occur between lectin-coated QDs (CuInS2 QDs-Con A conjugates, acceptors) and carbohydrate-coated RB (RB-NH2-glu conjugates, donors). The fluorescence of lectin-coated QDs was recovered in the presence of a glycoprotein such as glucose oxidase (GOx) and transferrin (TRF), which significantly reduced the FRET efficiency between the donor and the acceptor. Under optimal conditions, a linear correlation was established between the fluorescence intensity ratio I654/I577 and the TRF concentration over the range of 6.90 × 10(-10) to 3.45 × 10(-8) mol/L, with a detection limit of 2.5 × 10(-10) mol/L. The linear range for GOx is 3.35 × 10(-10) to 6.70 × 10(-8) mol/L, with a detection limit of 1.5 × 10(-10) mol/L. The proposed method was applied to the determination of glycoprotein in human serum and cell-extract samples with satisfactory results. Furthermore, CuInS2 QDs-Con A conjugates are used as safe and efficient optical nanoprobes in HepG2 cell imaging.
基于硫化铜铟量子点（QDs）与罗丹明B（RB）之间的荧光共振能量转移（FRET），建立了一种高灵敏度的糖蛋白检测荧光方法。凝集素是一类对碳水化合物结构具有独特亲和力的蛋白质，因此在凝集素包被的量子点（硫化铜铟量子点-伴刀豆球蛋白A缀合物，受体）与碳水化合物包被的罗丹明B（RB-NH2-葡萄糖缀合物，供体）之间可发生FRET过程。在存在糖蛋白如葡萄糖氧化酶（GOx）和转铁蛋白（TRF）的情况下，凝集素包被量子点的荧光得以恢复，这显著降低了供体与受体之间的FRET效率。在最佳条件下，荧光强度比I654/I577与TRF浓度在6.90×10(-10)至3.45×10(-8) mol/L范围内呈线性相关，检测限为2.5×10(-10) mol/L。GOx的线性范围为3.35×10(-10)至6.70×10(-8) mol/L，检测限为1.5×10(-10) mol/L。所提出的方法应用于人体血清和细胞提取物样品中糖蛋白的测定，结果令人满意。此外，硫化铜铟量子点-伴刀豆球蛋白A缀合物在HepG2细胞成像中用作安全有效的光学纳米探针。
