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DNA-Functionalized Gold Nanoparticles
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Finally, certain DNA sequences also have excellent molecular binding properties, and such binding DNAs are known as aptamers. Aptamers are often isolated via a combinatorial biology technique called systematic evolution of ligands by exponential enrichment (SELEX) (Tuerk and Gold 1990, Ellington and Szostak 1990). To date, hundreds of aptamers targeting small molecules, proteins and even live cells have been reported. DNA can also perform enzyme-like catalytic functions, and these are called DNAzymes or deoxyribozymes (Joyce 2004). DNAzymes are isolated using a similar selection method, and they require metal ions for catalysis. Such a metal requirement has made DNAzymes useful for metal detection. Therefore, DNA has both excellent structural and functional properties. Combined with its high stability and low cost of synthesis as well as ease of modification, DNA is a highly attractive molecule for interfacing with AuNPs (Rosi and Mirkin 2005, Liu 2012, Tan et al. 2014, Wang et al. 2009, Song et al. 2010, Zhao et al. 2008).
Artificial Enzymes
Published in Yubing Xie, The Nanobiotechnology Handbook, 2012
James A. Stapleton, Agustina Rodriguez-Granillo, Vikas Nanda
So far, we have reviewed the major class of artificial enzymes: those composed of protein. However, another important class of biological enzymes is not protein-based but is instead based on nucleic acids. These are termed ribozymes or deoxyribozymes, depending on whether they are composed of RNA or DNA. Here, we will focus only on artificial ribozymes.
Beyond the smiley face: applications of structural DNA nanotechnology
Published in Nano Reviews & Experiments, 2018
Aakriti Alisha Arora, Chamaree de Silva
As nanorobots possess the ability for controlled dynamic movement, molecular spiders allow for more complex behavior [26]. Molecular spiders consist of a streptavidin body with three catalytic legs comprised deoxyribozymes [26]. The environment onto which the spider walks is a precisely defined DNA origami landscape. The landscape and complementary oligonucleotides allow for the spider to autonomously ‘start’, ‘follow’, ‘turn’, and ‘stop’ [26]. The track comprised DNA substrates, which are bound to the deoxyribozyme legs; the deoxyribozyme cleaves the substrate, and creates two short products [26]. Cleavage allows for the dissociation of the legs, which could then associate with the next substrate, allowing the spider to move. The spider begins to ‘walk’ after introduction with an ssDNA trigger, but once it reached a stop site on the landscape, it stops moving. The spider was tactfully designed to exhibit ‘memory’; that is, the deoxyribozyme leg dissociates faster if it reaches a site upon which it had previously visited. Hence, molecular spiders have the potential to provide the basis for initiating programmable behaviors of nanostructures in various complex environments [26].