Abstract
A fluorometric assay is described for highly sensitive quantification of Escherichia coli O157:H7. Reporter oligos were immobilized on graphene quantum dots (GQDs), and quencher oligos were immobilized on gold nanoparticles (AuNPs). Target DNA was co-hybridized with reporter oligos on the GQDs and quencher oligos on AuNPs. This triggers quenching of fluorescence (with excitation/emission peaks at 400nm/530nm). On introducing target into the system, fluorescence is quenched by up to 95% by 100nM concentrations of target oligos having 20bp. The response to the fliC gene of E. coli O157:H7 increases with the logarithm of the concentration in the range from 0.1nM to 150nM. The limit of detection is 1.1 ± 0.6nM for n = 3. The selectivity and specificity of the assay was confirmed by evaluating the various oligos sequences and PCR product (fliC gene) amplified from genomic DNA of the food samples spiked with E. coli O157:H7. Graphical abstractSchematic representation of fluorometric assay for highly sensitive quantification of Escherichia coli O157:H7 based on fluorescence quenching gene assay for fliC gene of E. coli O157:H7.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
