One-pot synthesis of strongly fluorescent DNA-CuInS2 quantum dots for label-free and ultrasensitive detection of anthrax lethal factor DNA.
Herein, high quality DNA-CuInS2 QDs are facilely synthesized through a one-pot hydrothermal method with fluorescence quantum yield as high as 23.4%, and the strongly fluorescent DNA-CuInS2 QDs have been utilized as a novel fluorescent biosensor for label-free and ultrasensitive detection of anthrax lethal factor DNA. L-Cysteine (L-Cys) and a specific-sequence DNA are used as co-ligands to stabilize the CuInS2 QDs. The specific-sequence DNA consists of two domains: phosphorothiolates domain (sulfur-containing variants of the usual phosphodiester backbone) controls the nanocrystal passivation and serves as a ligand, and the functional domain (non-phosphorothioates) controls the biorecognition. The as-prepared DNA-CuInS2 QDs have high stability, good water-solubility and low toxicity. Under the optimized conditions, a linear correlation was established between the fluorescence intensity ratio I/I0 (I0 is the original fluorescence intensity of DNA-CuInS2 QDs, and I is the fluorescence intensity of DNA-CuInS2 QDs/GO with the addition of various concentrations of anthrax lethal factor DNA) and the concentration of anthrax lethal factor DNA in the range of 0.029-0.733 nmol L-1 with a detection limit of 0.013 nmol L-1. The proposed method has been successfully applied to the determination of anthrax lethal factor DNA sequence in human serum samples with satisfactory results. Because of low toxicity and fine biocompatibility, DNA-CuInS2 QDs also hold potential applications in bioimaging.
['Liu|Ziping|Z|', 'Su|Xingguang|X|']
D000942:Antigens, Bacterial D001427:Bacterial Toxins D015374:Biosensing Techniques D003300:Copper D004247:DNA D004269:DNA, Bacterial D005453:Fluorescence D007204:Indium D057230:Limit of Detection D045663:Quantum Dots D017550:Spectroscopy, Fourier Transform Infrared D013440:Sulfides
One-pot synthesis Anthrax lethal factor DNA Fluorescence biosensor DNA-QDs Graphene oxide