title: Highly sensitive fluorescence detection of glycoprotein based on energy transfer between CuInS2 QDs and rhodamine B.
abstract: 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.
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Xue
authors: X
authors: Gao
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Dan
authors: D
authors: Li
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Ying
authors: Y
authors: Tong
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Dan
authors: D
authors: Ge
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Yiwei
authors: Y
authors: Tang
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Defu
authors: D
authors: Zhang
authors: College of Chemistry, Chemical Engineering and Food Safety, Bohai University, Jinzhou, 121013, People's Republic of China.
authors: Jianrong
authors: J
authors: Li
mesh_terms: D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D056945:Hep G2 Cells; D006801:Humans; D037102:Lectins / Q000737:chemistry; D057230:Limit of Detection; D011485:Protein Binding; D045663:Quantum Dots / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D006023:Glycoproteins; D037102:Lectins; D012235:Rhodamines; C029773:rhodamine B
keywords: CuInS2 QDs; HepG2 cells; fluorescence resonance energy transfer; glycoprotein