Nanotechnology and aptamers: applications in drug delivery

Nucleic acid ligands, also known as aptamers, are a class of macromolecules that are being used in several novel nanobiomedical applications. Aptamers are characterized by high affinity and specificity for their target, a versatile selection process, ease of chemical synthesis and a small physical size, which collectively make them attractive molecules for targeting diseases or as therapeutics. These properties will enable aptamers to facilitate innovative new nanotechnologies with applications in medicine. In this review, we will highlight recent developments in using aptamers in nanotechnology solutions for treating and diagnosing disease.

Aptamer-based biosensors

Nucleic-acid aptamers have attracted intense interest and found wide applications in a range of areas. In this review, we summarize recent advances in the development of aptamer-based biosensors and bioassay methods, most of which have employed electrochemical, optical and mass-sensitive analytical techniques. Aptamers exhibit many advantages as recognition elements in biosensing when compared to traditional antibodies. They are small in size, chemically stable and cost effective. More importantly, aptamers offer remarkable flexibility and convenience in the design of their structures, which has led to novel biosensors that have exhibited high sensitivity and selectivity. Recently, the combination of aptamers with novel nanomaterials has significantly improved the performance of aptamer-based sensors, which we also review in this article. In view of the unprecedented advantages brought by aptamers, we expect aptamer-based biosensors to find broad applications in biomedical diagnostics, environmental monitoring and homeland security.

Keywords: Aptamer; Biosensor; Nanomaterial; Nanotechnology

Aptamers as recognition elements for label-free analytical devices

In spite of the impressive advances in aptasensing, the search for label-free devices for the detection of the aptamer-ligand interaction is still a challenge. This review highlights the advantages and the limitations of using label-free detection strategies and summarizes the state of the art in this field.