Synthesis of water soluble CuGaS2/ZnS quantum dots for ultrasensitive fluorescent detection of alkaline phosphatase based on inner filter effect
Huangfu, XX (Huangfu, Xiaoxia)[ 1 ] ; Shen, Y (Shen, Yang)[ 1 ] ; Yang, AZ (Yang, Anzi)[ 1 ] ; Liu, LX (Liu, Lixiao)[ 1 ] ; Luo, W (Luo, Wen)[ 1 ] ; Zhao, WB (Zhao, Wenbo)[ 1 ]*（赵文波）
[ 1 ]Nanjing Normal Univ, Natl & Local Joint Engn Res Ctr Biomed Funct Mat, Sch Chem & Mat Sci, Nanjing 210023, Peoples R China
COLLOIDS AND SURFACES B-BIOINTERFACES，202007,191,110984
Developing monitoring technique for alkaline phosphatase (ALP) is crucial due to the important role it plays in living cells. Here, a kind of biocompatible glutathione-modified CuGaS2/ZnS quantum dots (GSH-CGS/ZnS QDs) was used as a fluorescent substance and then fabricated "turn-off" fluorescent biosensor for detection of ALP by help of inner filter effect (IFE). Firstly, we prepared CuGaS2/ZnS (CGS/ZnS) QDs using solvothermal method and explored the efficient ligand (GSH) exchanges strategy for transferring oil-soluble CGS/ZnS QDs to aqueous phase. More importantly, we also explored the potential biological applications of the nanohybrid QDs. The obtained GSH-CGS/ZnS QDs emitted strong yellow fluorescence with the maximum excitation (400 nm) and emission (601 nm). Then, GSH-CGS/ZnS QDs were mixed with p-nitrophenylphosphate (PNPP) and ALP. PNPP could be hydrolyzed to p-nitrophenol (PNP) by help of catalysis of ALP, and the excitation spectrum of the GSH-CGS/ZnS QDs overlapped well with the absorption spectrum of PNP, so the fluorescence of GSH-CGS/ZnS QDs was initially quenched via the so-called "IFE". Finally, a novel "turn-off" biosensor for sensitive detection of ALP in the range of 0.05-10 U L-1 (R-2 = 0.98) with a detection limit of 0.01 U L-1. was successfully obtained. Results indicated that I-III-VI2 nanocrystals have great potential for their promising biomedical application.