Trends in DNA biosensors

Abstract

Biosensors have witnessed an escalating interest nowadays, both in the research and commercial fields. Deoxyribonucleic acid (DNA) biosensors (genosensors) have been exploited for their inherent physico-chemical stability and suitability to discriminate different organism strains. The main principle of detection among genosensors relies on specific DNA hybridization, directly on the surface of a physical transducer. This review covers the main DNA immobilization techniques reported so far, new micro- and nanotechnological platforms for biosensing and the transduction mechanisms in genosensors. Clinical applications, in particular, demand large-scale and decentralized DNA testing. New schemes for DNA diagnosis include DNA chips and microfluidics, which couples DNA detection with sample pretreatment under in vivo-like hybridization conditions. Higher sensitivity and specificity may arise from nanoengineered structures, like carbon nanotubes (CNTs) and DNA/protein conjugates. A new platform for universal DNA biosensing is also presented, and its implications for the future of molecular diagnosis are argued.