Electrochemical aptasensor arrays have been recently used to detect several proteins reported as disease biomarkers, mainly due to their known advantages, that include high affinity, sensitivity, specificity and low costs, among others. This study describes the development of a label-free electrochemical multi-aptasensor array, for the simultaneous detection of human osteopontin (OPN), using two specific aptamers. To enable multiplexed protein assay, RNA and DNA aptamers were immobilized in the dual-screen-printed gold working electrodes via streptavidin-biotin interaction, and using the [Fe(CN)6]3-/4- as the redox probe for cyclic voltammetry measurements. The multi-aptasensor array herein developed exhibited a good response and selectivity to detect human OPN in the presence of other interfering proteins. Considering these preliminary results, the DNA/RNA dual aptasensor array could potentially be used as an analytical tool for the specific detection of human OPN, and for cancer diagnosis overall.

Doença da tinta é um das doenças mais destrutivas em Castanea sativa. Os sintomas mais comuns são necroses e uma redução em crescimento da raiz que invariavelmente leva à morte das plantas. Phytophthora cinnamomi é o oomycete associado a esta doença cujo ciclo de vida acontece integralmente no solo. Foi obtido um fragmento com 1231pb do gene glucan endo-1,3-β-D-glucosidase por amplificação usando oligonucleotidos conservados e a sequência completa do gene foi obtido flanqueando esta sequência conhecida por PCR assimétrico. Este fragmento foi obtido de ADN genómico de Phytophthora cinnamomi isolado por nós nas Regiões Europeias de Castilla-Léon (Espanha) e Trás-os-Montes (Portugal) e associado à doença da tinta da Castanea sativa Mill.

Ink disease is one of the most destructive diseases in Castanea sativa. The most common symptoms are root necrosies and a reduction in root growth, which invariably lead to the death of the trees. Phytophthora cinnamomi is an oomycete associated with this disease whose life cycle develops integrally in the soil. In the present work, was a fragment with 1231bp of the glucan endo-1,3-β-D-glucosidase gene obtained by amplification, using conserved primers and the full-length gene sequence by flanking this known sequence by asymmetric PCR. This fragment was obtained from genomic DNA of Phytophthora cinnamomi isolated in the European Regions of Castilla-Leon (Spain) and Trás-os-Montes (Portugal) and associated with the ink disease of Castanea sativa Mill.