Liu Ziping, Su Xingguang
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Anal Chim Acta. 2016 Oct 26;942:86-95. doi: 10.1016/j.aca.2016.09.004. Epub 2016 Sep 8.
Herein, high quality DNA-CuInS QDs are facilely synthesized through a one-pot hydrothermal method with fluorescence quantum yield as high as 23.4%, and the strongly fluorescent DNA-CuInS 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 CuInS 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-CuInS 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/I (I is the original fluorescence intensity of DNA-CuInS QDs, and I is the fluorescence intensity of DNA-CuInS 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 with a detection limit of 0.013 nmol L. 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-CuInS QDs also hold potential applications in bioimaging.
在此，通过一锅水热法轻松合成了高质量的DNA-CuInS量子点，其荧光量子产率高达23.4%，并且强荧光DNA-CuInS量子点已被用作一种新型荧光生物传感器，用于无标记和超灵敏检测炭疽致死因子DNA。L-半胱氨酸（L-Cys）和特定序列的DNA用作共配体来稳定CuInS量子点。特定序列的DNA由两个结构域组成：硫代磷酸酯结构域（通常磷酸二酯主链的含硫变体）控制纳米晶体的钝化并作为配体，功能结构域（非硫代磷酸酯）控制生物识别。所制备的DNA-CuInS量子点具有高稳定性、良好的水溶性和低毒性。在优化条件下，荧光强度比I/I（I是DNA-CuInS量子点的原始荧光强度，I是添加不同浓度炭疽致死因子DNA后的DNA-CuInS量子点/氧化石墨烯的荧光强度）与炭疽致死因子DNA浓度在0.029 - 0.733 nmol/L范围内呈线性相关，检测限为0.013 nmol/L。该方法已成功应用于人体血清样本中炭疽致死因子DNA序列的测定，结果令人满意。由于低毒性和良好的生物相容性，DNA-CuInS量子点在生物成像方面也具有潜在应用。
