Emerging applications of aptamers to micro- and nanoscale biosensing

Micro- and nanofabrication has allowed the production of ultra-sensitive, portable, and inexpensive biosensors. These devices generally rely on chemical or biological receptors which recognize a particular compound of interest and relay this recognition event effectively by transduction. Recent advances in RNA and DNA synthesis have enabled the use of aptamers, in vitro generated oligonucleotides, which offer high affinity biomolecular recognition to a theoretically limitless variety of analytes. DNA and RNA aptamers have gained so much attention in the biosensor community, that they have begun competing with more established affinity ligands including enzymes, lectins, and most notably, immunoreceptors such as antibodies. This article reviews the current state-of-the-art of aptasensors, or biosensors that use aptamers as molecular recognition elements, emphasizing the synergy between aptamer-based biosensing and micro- and nanotechnology. Aptasensors developed on micro- and nanoscale platforms based on mass changes, electroanalytical techniques, optical transduction, and purification and separation methods will be covered.