RESUMO
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 400 nm/530 nm). On introducing target into the system, fluorescence is quenched by up to 95% by 100 nM concentrations of target oligos having 20 bp. The response to the fliC gene of E. coli O157:H7 increases with the logarithm of the concentration in the range from 0.1 nM to 150 nM. The limit of detection is 1.1 ± 0.6 nM 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.
Assuntos
DNA Bacteriano/análise , Escherichia coli O157/isolamento & purificação , Grafite/química , Nanopartículas Metálicas/química , Pontos Quânticos/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Animais , Queijo/microbiologia , DNA Bacteriano/genética , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Flagelina/genética , Contaminação de Alimentos/análise , Ouro/química , Ácidos Nucleicos Imobilizados/química , Ácidos Nucleicos Imobilizados/genética , Hibridização de Ácido Nucleico , Aves Domésticas/microbiologiaRESUMO
Gene therapy is a promising approach towards cancer treatment. The main aim of the therapy is to destroy cancer cells, usually by apoptotic mechanisms, and preserving others. However, its application has been hindered by many factors including poor cellular uptake, non-specific cell targeting and undesirable interferences with other genes or gene products. A variety of strategies exist to improve cellular uptake efficiency of gene-based therapies. This paper highlights advancements in gene therapy research and its application in relation to anti-cancer treatment.