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Published on: October 13, 2017
Graphene Oxide Quantum Dots Assisted Construction of Fluorescent Aptasensor for Rapid Detection of Pseudomonas
Ran Gao1, Zitao Zhong1, Xiaomei Gao1
1Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics , South China Normal University , Guangzhou 510631 , China.
Abstract:
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 × 103-2.00 × 107 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.
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