title: One-pot synthesis of strongly fluorescent DNA-CuInS2quantum dots for label-free and ultrasensitive detection of anthrax lethal factor DNA.
abstract: Herein, high quality DNA-CuInS2QDs are facilely synthesized through a one-pot hydrothermal method with fluorescence quantum yield as high as 23.4%, and the strongly fluorescent DNA-CuInS2QDs 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 CuInS2QDs. 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-CuInS2QDs 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(I0is the original fluorescence intensity of DNA-CuInS2QDs, and I is the fluorescence intensity of DNA-CuInS2QDs/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-1with 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-CuInS2QDs also hold potential applications in bioimaging.
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors.forename: Ziping
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China. Electronic address: suxg@jlu.edu.cn.
authors.forename: Xingguang
authors.initials: X
authors.lastname: Su
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D015374:Biosensing Techniques; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004269:DNA, Bacterial / Q000097:blood / Q000302:isolation & purification*; D005453:Fluorescence; D007204:Indium / Q000737:chemistry*; D057230:Limit of Detection; D045663:Quantum Dots; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry*
chemical_list: D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D013440:Sulfides; C030325:anthrax toxin; D007204:Indium; D003300:Copper; D004247:DNA
keywords: Anthrax lethal factor DNA; DNA-QDs; Fluorescence biosensor; Graphene oxide; One-pot synthesis