Desenvolvimento de um biossensor amperomÃtrico de DNA para detecÃÃo do PapilomavÃrus humano

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The cervical cancer has been a serious problem in Brazil and in the world wuith about 18.680 infected woman annually. The Human Papillomavirus (HPV) has been biologically associated with the development of cervical lesions, due to its capacity to infect epithelial cells and progress to cervical uterine cancer. The late screening may unviable the treatment, leading to death many woman. This screening could be earlier with the use of DNA biosensors, that are analytical devices that result from the integration of a sequence specific probe and a signal transducer. Among other electrochemical techniques, amperometric biosensors have been recently described as attractive due to their simplicity, low instrumentation costs, possibility for real time and generally high sensitivity. In this work a genosensor was developed for detection of DNA sequences of the virus HPV using methylen blue as chemical mediator. The biology signals were transducer by Diferencial Pulse Voltametric (DPV). The work and reference electrodes were constructed using imprinting technique on a polyvinyl alcohol support. They were made with carbon paste and AgAgCl respectively. The work electrode was modified with chitosan for the immobilization of short sequences of DNA for hybridization with another target sequence. The target sequence used for the hybridization was the gene E6 HPV-18, a long chain with 500 base pairs available for annealing with sequences with 20 bases. Bioinformatics analyses were realized to verify possible regions for annealing of the sequences in viral genome. The results demonstrated an increase in the signal of the methylene blue when the hybridization occurred, showed by the increasing in DVP current peaks, graphically analyzed. The differences between the signals emitted from, an electrode with hybridizations reactions and other without them, was used to detect viral DNA sequences from clinical samples. The reported findings indicate the possibility applications of the method in clinical screening, and confirm the imprinting technique as a viable instrument for construction of DNA biosensors using methylene blue as an indicator of hybridization signals

ASSUNTO(S)

biossensor biologia molecular hpv-18 hpv-18 cervical cancer biosensor methylene blue azul de metileno cÃncer cervical

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