Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics , South China Normal University , Guangzhou 510631 , China.
J Agric Food Chem. 2018 Oct 17;66(41):10898-10905. doi: 10.1021/acs.jafc.8b02164. Epub 2018 Oct 3.
We engineered an ingenious fluorescent aptasensor for detection of Pseudomonas aeruginosa ( P. aeruginosa) according to the DNA hybridization and fluorescence resonance energy transfer. In the absence of target bacteria, 5-carboxyfluorescein-labeled complementary DNA (FAM-cDNA) hybridizes with the partial sequences of aptamer and the fluorescence of FAM can be quenched by graphene oxide quantum dots (GOQDs). Upon the addition of target bacteria, the aptamer as a biorecognition element is bound with P. aeruginosa specifically. FAM-cDNA prefers to hybridize with the aptamer, resulting in the desorption of FAM-cDNA from GOQDs, thus recovering the fluorescence of FAM. The aptasensor shows a wide linear response to P. aeruginosa in the concentration range of 1.28 × 10-2.00 × 10 cfu/mL with acceptable selectivity. The detection limit is 100 cfu/mL. The whole process can be finished in 2 h. Moreover, the platform is successfully applied to detect P. aeruginosa in drinking water, orange juice, and popsicle samples.
我们根据 DNA 杂交和荧光共振能量转移原理，设计了一种巧妙的荧光适体传感器来检测铜绿假单胞菌（P. aeruginosa）。在没有目标细菌的情况下，5-羧基荧光素标记的互补 DNA（FAM-cDNA）与适体的部分序列杂交，并且荧光素的荧光可以被石墨烯量子点（GOQDs）猝灭。当加入目标细菌时，适体作为生物识别元件特异性地与铜绿假单胞菌结合。FAM-cDNA 优先与适体杂交，导致 FAM-cDNA 从 GOQDs 上解吸，从而恢复 FAM 的荧光。该适体传感器在 1.28×10-2.00×10 cfu/mL 的浓度范围内对铜绿假单胞菌表现出宽的线性响应，具有可接受的选择性。检测限为 100 cfu/mL。整个过程可以在 2 小时内完成。此外，该平台成功应用于饮用水、橙汁和冰棒样品中铜绿假单胞菌的检测。
