Asma Khoobi - Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan ۹۸۱۳۵-۶۷۴, Iran

DNA biosensors based on nucleic acid hybridization have been actively developed due totheir portability, speed, specificity, and low cost. Recently, using nanostructured materials forDNA biosensors are interest and important. The materials are favorite because of excellentbiological compatibilities and their high surface-to volume ratios. Therefore, the nanomaterialsare used to increase the amount of DNA immobilization. Also, DNA bound tonanostructured materials can maintain its biological activity. Additionally, signalamplification by labeling a targeted analyte with nanostructured materials has also beenobtained for DNA biosensors in many reports. This present study summarizes theapplications of numerous nanostructured materials for DNA biosensors. The reports havebeen shown that nanostructured materials due to small sizes were advantageous as substratesfor DNA attachment or as labels for signal amplification; and application of nanocompositesin the biosensors can be enhanced their overall quality and to overcome the deficiencies ofthe individual nano-components. Two main signal amplification approaches have been usedcontaining labeling double-stranded DNA (ds-DNA) with either a reversible electron transfermediator or a nanocatalyst that can mediate the electrolysis of a large quantity of substrateand increasing the loading of electroactive species, often by metallic or semiconductornanoparticle labels, e.g. Au, Ag, ZnS, CdS, and PbS. In these cases, the large amount ofmetal atoms per nanoparticle label creates significant signal amplification. Furthermore, theapplication of different nanostructured materials for different target analyte offers excellentmultiplexing capabilities. However, additional development of nanostructured materials withsmaller size and with enhanced chemical and biological properties would substantiallyimprove the selectivity, accuracy and sensitivity of DNA biosensors.

DNA, Biosensor, Nanomaterials, Gold nanostructures