Label-free electrochemical DNA biosensor for zika virus detection sequences

This study describes an impedimetric electrochemical DNA biosensor for label-free detection of zika virus. Disposable electrodes were fabricated by thermal evaporation on polyethylene terephthalate substrates covered with a nanometric gold layer manufactured in three-contact configurations. The disposable, evaporated electrodes were morphologically characterized by atomic force microscopy and scanning electron microscopy. The electrode surface was characterized by electroanalytical techniques. Genetic sequences of primers and complementary capture probes were designed based on analysis of the zika and dengue virus genomes. The biosensor used a three-contact electrode to identify DNA sequences in a drop of sample, and for detection of zika virus sequences, it allowed for direct reading of the hybridization event without labeling on disposable electrodes and with a 1.5 hour response time. In this system, impedance measurements indicated a limit of detection of 25.0 ± 1.7 nM. The developed biosensors showed selectivity for zika in the synthetic DNA assays, and therefore, are promising for clinical analysis.
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research