Graphene Oxide Quantum Dots Assisted Construction of Fluorescent Aptasensor for Rapid Detection of Pseudomonas aeruginosa in Food Samples
journal contributionposted on 24.09.2018, 00:00 authored by Ran Gao, Zitao Zhong, Xiaomei Gao, Li Jia
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.