Aptamers (from the Latin aptus – fit, and Greek meros – part) are oligonucleotide or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist in riboswitches. Aptamers can be used for both basic research and clinical purposes as macromolecular drugs. Aptamers can be combined with ribozymes to self-cleave in the presence of their target molecule. These compound molecules have additional research, industrial and clinical applications.
More specifically, aptamers can be classified as
- DNA or RNA or XNA aptamers. They consist of (usually short) strands of oligonucleotides.
- Peptide aptamers. They consist of one (or more) short variable peptide domains, attached at both ends to a protein scaffold.
Nucleic acid aptamers are nucleic acid species (next-gen antibody mimics) that exhibit affinity for a given target with selectivity and specificity comparable to antibodies. Nucleic acid aptamers can consist of either RNA or DNA. Nucleic acid aptamers are generated via in-vitro selection methods such as SELEX (systematic evolution of ligands by exponential enrichment) to express affinity for targets ranging from small ligands such as heavy metal ions and small molecules, up to larger lignads such as proteins and cells. At the molecular level, the aptamer-ligand interaction is mediated through non-covalent forces; electrostatic interactions, hydrophobic interactions, pi-pi orbital stacking, and hydrogen bonding interactions. The molecular recognition properties of aptamers present growing use in biotechnological and therapeutic applications. Aptamers offer advantages over antibodies as they can be engineered completely in vitro, are readily produced by chemical synthesis, possess desirable storage properties, and elicit little or no immunogenicity in therapeutic applications.
In 1990, two labs independently developed the technique of selection: the Gold lab, using the term SELEX for their process of selecting RNA ligands against T4 DNA polymerase; and the Szostak lab, coining the term in vitro selection, selecting RNA ligands against various organic dyes. The Szostak lab also coined the term aptamer (from the Latin, apto, meaning 'to fit') for these nucleic acid-based ligands. Two years later, the Szostak lab and Gilead Sciences, independent of one another, used in vitro selection schemes to evolve single stranded DNA ligands for organic dyes and human coagulant, thrombin (see anti-thrombin aptamers), respectively. There does not appear to be any systematic differences between RNA and DNA aptamers, save the greater intrinsic chemical stability of DNA.
The notion of selection in vitro was preceded twenty-plus years prior when Sol Spiegelman used a Qbeta replication system as a way to evolve a self-replicating molecule. In addition, a year before the publishing of in vitro selection and SELEX, Gerald Joyce used a system that he termed 'directed evolution' to alter the cleavage activity of a ribozyme.
Since the discovery of aptamers, many researchers have used aptamer selection as a means for application and discovery. In 2001, the process of in vitro selection was automated by J. Colin Cox in the Ellington lab at the University of Texas at Austin, reducing the duration of a selection experiment from six weeks to three days.
While the process of artificial engineering of nucleic acid ligands is highly interesting to biology and biotechnology, the notion of aptamers in the natural world had yet to be uncovered until 2002 when two groups led by Ronald Breaker and Evgeny Nudler discovered a nucleic acid-based genetic regulatory element (which was named riboswitch) that possesses similar molecular recognition properties to the artificially made aptamers. In addition to the discovery of a new mode of genetic regulation, this adds further credence to the notion of an 'RNA World', a postulated stage in time in the origins of life on Earth.
Both DNA and RNA aptamers show robust binding affinities for various targets. DNA and RNA aptamers have been selected for the same target. These targets include lysozyme, thrombin, human immunodeficiency virus trans-acting responsive element (HIV TAR), hemin, interferon γ, vascular endothelial growth factor (VEGF), prostate specific antigen (PSA), dopamine, and the non-classical oncogene, heat shock factor 1 (HSF1). In the case of lysozyme, HIV TAR, VEGF and dopamine the DNA aptamer is the analog of the RNA aptamer, with thymine replacing uracil. The hemin, thrombin, and interferon γ, DNA and RNA aptamers were selected through independent selections and have unique sequences. Considering that not all DNA analogs of RNA aptamers show functionality, the correlation between DNA and RNA sequence and their structure and function requires further investigation.
Lately, a concept of smart aptamers, and smart ligands in general, has been introduced. It describes aptamers that are selected with pre-defined equilibrium (), rate (, ) constants and thermodynamic (ΔH, ΔS) parameters of aptamer-target interaction. Kinetic capillary electrophoresis is the technology used for the selection of smart aptamers. It obtains aptamers in a few rounds of selection.
Recent developments in aptamer-based therapeutics have been rewarded in the form of the first aptamer-based drug approved by the U.S. Food and Drug Administration (FDA) in treatment for age-related macular degeneration (AMD), called Macugen offered by OSI Pharmaceuticals. In addition, the company NeoVentures Biotechnology Inc. has successfully commercialized the first aptamer based diagnostic platform for analysis of mycotoxins in grain. Many contract companies develop aptamers and aptabodies to replace antibodies in research, diagnostic platforms, drug discovery, and therapeutics.
Non-modified aptamers are cleared rapidly from the bloodstream, with a half-life of minutes to hours, mainly due to nuclease degradation and clearance from the body by the kidneys, a result of the aptamer's inherently low molecular weight. Unmodified aptamer applications currently focus on treating transient conditions such as blood clotting, or treating organs such as the eye where local delivery is possible. This rapid clearance can be an advantage in applications such as in vivo diagnostic imaging. An example is a tenascin-binding aptamer under development by Schering AG for cancer imaging. Several modifications, such as 2'-fluorine-substituted pyrimidines, polyethylene glycol (PEG) linkage, etc. (both of which are used in Macugen, an FDA-approved aptamer) are available to scientists with which to increase the serum half-life of aptamers easily to the day or even week time scale.
Another approach to increase the nuclease resistance of aptamers is to develop Spiegelmers, which are composed entirely of an unnatural L-ribonucleic acid backbone. A Spiegelmer of the same sequence has the same binding properties of the corresponding RNA aptamer, except it binds to the mirror image of its target molecule.
In addition to the development of aptamer-based therapeutics, many researchers such as the Ellington lab have been developing diagnostic techniques for aptamer based plasma protein profiling called aptamer plasma proteomics. This technology will enable future multi-biomarker protein measurements that can aid diagnostic distinction of disease versus healthy states.
Furthermore, the Hirao lab applied a genetic alphabet expansion using an unnatural base pair to SELEX and achieved the generation of high affinity DNA aptamers. Only a few hydrophobic interactions from an unnatural fifth base significantly augments the aptamer affinity to target proteins.
As a resource for all in vitro selection and SELEX experiments, the Ellington lab has developed the Aptamer Database cataloging all published experiments.
Optimer ligands are next-generation aptamers. Based on aptamer technology, Optimer ligands are selected through iterative rounds of in vitro selection to identify ligands that bind with high specificity, low cross-reactivity and specific binding kinetics. Following discovery they are further engineered to offer increased stability, smaller size and improved manufacturability. The improved manufacturing profile of Optimer ligands increases scalability, lot-to-lot consistency and reduces cost compared to standard aptamers.
Split aptamers are composed of two or more DNA strands that mimic segments of a larger parent aptamer. The ability of each component strand to bind targets will depend on the location of the nick and the secondary structures of the daughter strands, with the most prominent structures being three-way junctions. The presence of a target molecule can promote assembly of the DNA fragments. Once assembled, the strands can be chemically or enzymatically ligated into a single strand. Analytes for which split aptamers have been developed include the protein α-thrombin, ATP, and cocaine. Split aptamers are a potential template for biosensors in analogy to split protein systems.
Peptide aptamers  are artificial proteins selected or engineered to bind specific target molecules. These proteins consist of one or more peptide loops of variable sequence displayed by a protein scaffold. They are typically isolated from combinatorial libraries and often subsequently improved by directed mutation or rounds of variable region mutagenesis and selection. In vivo, peptide aptamers can bind cellular protein targets and exert biological effects, including interference with the normal protein interactions of their targeted molecules with other proteins. Libraries of peptide aptamers have been used as "mutagens", in studies in which an investigator introduces a library that expresses different peptide aptamers into a cell population, selects for a desired phenotype, and identifies those aptamers that cause the phenotype. The investigator then uses those aptamers as baits, for example in yeast two-hybrid screens to identify the cellular proteins targeted by those aptamers. Such experiments identify particular proteins bound by the aptamers, and protein interactions that the aptamers disrupt, to cause the phenotype. In addition, peptide aptamers derivatized with appropriate functional moieties can cause specific postranslational modification of their target proteins, or change the subcellular localization of the targets.
Peptide aptamers can also recognize targets in vitro. They have found use in lieu of antibodies in biosensors  and used to detect active isoforms of proteins from populations containing both inactive and active protein forms. Derivatives known as tadpoles, in which peptide aptamer "heads" are covalently linked to unique sequence double-stranded DNA "tails", allow quantification of scarce target molecules in mixtures by PCR (using, for example, the quantitative real-time polymerase chain reaction) of their DNA tails.
The peptides that form the aptamer variable regions are synthesized as part of the same polypeptide chain as the scaffold and are constrained at their N and C termini by linkage to it. This double structural constraint decreases the diversity of the conformations that the variable regions can adopt, and this reduction in conformational diversity lowers the entropic cost of molecular binding when interaction with the target causes the variable regions to adopt a single conformation. As a consequence, peptide aptamers can bind their targets tightly, with binding affinities comparable to those shown by antibodies (nanomolar range).
Peptide aptamer scaffolds are typically small, ordered, soluble proteins. The first scaffold, which is still widely used, is Escherichia coli thioredoxin, the trxA gene product (TrxA). In these molecules, a single peptide of variable sequence is displayed instead of the Gly-Pro motif in the TrxA -Cys-Gly-Pro-Cys- active site loop. Improvements to TrxA include substitution of serines for the flanking cysteines, which prevents possible formation of a disulfide bond at the base of the loop, introduction of a D26A substitution to reduce oligomerization, and optimization of codons for expression in human cells,. Reviews in 2015 have reported studies using 12  and 20  other scaffolds.
Peptide aptamer selection can be made using different systems, but the most used is currently the yeast two-hybrid system. Peptide aptamers can also be selected from combinatorial peptide libraries constructed by phage display and other surface display technologies such as mRNA display, ribosome display, bacterial display and yeast display. These experimental procedures are also known as biopannings. Among peptides obtained from biopannings, mimotopes can be considered as a kind of peptide aptamers. All the peptides panned from combinatorial peptide libraries have been stored in a special database with the name MimoDB.
Selection of Ligand Regulated Peptide Aptamers (LiRPAs) has been demonstrated. By displaying 7 amino acid peptides from a novel scaffold protein based on the trimeric FKBP-rapamycin-FRB structure, interaction between the randomized peptide and target molecule can be controlled by the small molecule Rapamycin or non-immunosuppressive analogs.
X-Aptamers are a new generation of aptamers designed to improve on the binding and versatility of regular DNA/RNA- based aptamers. X-Aptamers are engineered with a combination of natural and chemically-modified DNA or RNA nucleotides. Base modifications allow incorporation of various functional groups/small molecules into X-aptamers, opening a wide range of uses and a higher likelihood of binding success compared to standard aptamers. Thiophosphate backbone modifications at selected positions enhance nuclease stability and binding affinity without sacrificing specificity.
X-Aptamers are able to explore new features by utilizing a new selection process. Unlike SELEX, X-Aptamer selection does not rely on multiple repeated rounds of PCR amplification but rather involves a two-step bead-based discovery process. In the primary selection process, combinatorial libraries are created where each bead will carry approximately 10^12 copies of a single sequence. The beads operate as carriers, where the bound sequences will ultimately be detached into solution. In the secondary solution pull-down process, each target will be used to individually pull down the binding sequences from solution. The binding sequences are amplified, sequenced, and analyzed. Sequences that are enriched for each target can then be synthesized and characterized. X-aptamers are commercially produced under the name "Raptamers" by a company called Raptamer Discovery Group.
Aptamers can be used as:
- Affinity reagents
- Bioimaging probes
- Sensing reagents
- Therapeutics, e.g. Pegaptanib.
- Controlled release of therapeutics
- Therapeutic delivery vehicles
- Clinical & environmental diagnostics 
- Reagents for High-Throughput Screening (HTS) of small molecules or proteins
- Protein Modification
Aptamers have also been generated against several pathogens both bacterial & viruses including influenza A and B viruses, Respiratory syncytial virus (RSV), SARS coronavirus (SARS-CoV) and SARS-CoV-2 in various experimental settings.
Aptamers have an innate ability to bind to any molecule to which they are targeted, including cancer cells and bacteria. Once bound to a target, aptamers can act as agonists or antagonists. Aptamers suffer from issues that limit their effectiveness: they're easily digested in vivo by nuclease enzymes.
Adding an unnatural base to a standard aptamer can increase its ability to bind to target molecules. A second addition in the form of a "mini hairpin DNA" gives the aptamer a stable and compact structure that is resistant to digestion, extending its life from hours to days.
Controlled release of therapeutics
The ability of aptamers to reversibly bind molecules such as proteins has generated increasing interest in using them to facilitate controlled release of therapeutic biomolecules, such as growth factors. This can be accomplished by tuning the affinity strength to passively release the growth factors, along with active release via mechanisms such as hybridization of the aptamer with complementary oligonucleotides or unfolding of the aptamer due to cellular traction forces.
- Kaur H, Shorie M (2019). "Nanomaterial based aptasensors for clinical and environmental diagnostic applications". Nanoscale Advances. 1 (6): 2123–38. Bibcode:2019NanoA...1.2123K. doi:10.1039/C9NA00153K.
- Mallikaratchy P (January 2017). "Evolution of Complex Target SELEX to Identify Aptamers against Mammalian Cell-Surface Antigens". Molecules. 22 (2): 215. doi:10.3390/molecules22020215. PMC 5572134. PMID 28146093.
- Mills DR, Peterson RL, Spiegelman S (July 1967). "An extracellular Darwinian experiment with a self-duplicating nucleic acid molecule". Proceedings of the National Academy of Sciences of the United States of America. 58 (1): 217–24. Bibcode:1967PNAS...58..217M. doi:10.1073/pnas.58.1.217. PMC 335620. PMID 5231602.
- Cox JC, Ellington AD (October 2001). "Automated selection of anti-protein aptamers". Bioorganic & Medicinal Chemistry. 9 (10): 2525–31. doi:10.1016/s0968-0896(01)00028-1. PMID 11557339.
- Cox JC, Rajendran M, Riedel T, Davidson EA, Sooter LJ, Bayer TS, et al. (June 2002). "Automated acquisition of aptamer sequences". Combinatorial Chemistry & High Throughput Screening. 5 (4): 289–99. doi:10.2174/1386207023330291. PMID 12052180.
- Cox JC, Hayhurst A, Hesselberth J, Bayer TS, Georgiou G, Ellington AD (October 2002). "Automated selection of aptamers against protein targets translated in vitro: from gene to aptamer". Nucleic Acids Research. 30 (20): 108e–108. doi:10.1093/nar/gnf107. PMC 137152. PMID 12384610.
- Svigelj R, Dossi N, Toniolo R, Miranda-Castro R, de-Los-Santos-Álvarez N, Lobo-Castañón MJ (September 2018). "Selection of Anti-gluten DNA Aptamers in a Deep Eutectic Solvent". Angewandte Chemie. 57 (39): 12850–54. Bibcode:2018AngCh.13013032S. doi:10.1002/ange.201804860. hdl:10651/49996. PMID 30070419. S2CID 240281828.
- Neves MA, Reinstein O, Saad M, Johnson PE (December 2010). "Defining the secondary structural requirements of a cocaine-binding aptamer by a thermodynamic and mutation study". Biophysical Chemistry. 153 (1): 9–16. doi:10.1016/j.bpc.2010.09.009. PMID 21035241.
- Baugh C, Grate D, Wilson C (August 2000). "2.8 A crystal structure of the malachite green aptamer". Journal of Molecular Biology. 301 (1): 117–28. doi:10.1006/jmbi.2000.3951. PMID 10926496.
- Dieckmann T, Fujikawa E, Xhao X, Szostak J, Feigon J (1995). "Structural Investigations of RNA and DNA aptamers in Solution". Journal of Cellular Biochemistry. 59: 13–81. doi:10.1002/jcb.240590703. S2CID 221833821.
- Potty AS, Kourentzi K, Fang H, Jackson GW, Zhang X, Legge GB, Willson RC (February 2009). "Biophysical characterization of DNA aptamer interactions with vascular endothelial growth factor". Biopolymers. 91 (2): 145–56. doi:10.1002/bip.21097. PMID 19025993. S2CID 23670.
- Long SB, Long MB, White RR, Sullenger BA (December 2008). "Crystal structure of an RNA aptamer bound to thrombin". RNA. 14 (12): 2504–12. doi:10.1261/rna.1239308. PMC 2590953. PMID 18971322.
- Darfeuille F, Reigadas S, Hansen JB, Orum H, Di Primo C, Toulmé JJ (October 2006). "Aptamers targeted to an RNA hairpin show improved specificity compared to that of complementary oligonucleotides". Biochemistry. 45 (39): 12076–82. doi:10.1021/bi0606344. PMID 17002307.
- Liu M, Kagahara T, Abe H, Ito Y (2009). "Direct In Vitro Selection of Hemin-Binding DNA Aptamer with Peroxidase Activity". Bulletin of the Chemical Society of Japan. 82: 99–104. doi:10.1246/bcsj.82.99.
- Min K, Cho M, Han SY, Shim YB, Ku J, Ban C (July 2008). "A simple and direct electrochemical detection of interferon-gamma using its RNA and DNA aptamers". Biosensors & Bioelectronics. 23 (12): 1819–24. doi:10.1016/j.bios.2008.02.021. PMID 18406597.
- Ng EW, Shima DT, Calias P, Cunningham ET, Guyer DR, Adamis AP (February 2006). "Pegaptanib, a targeted anti-VEGF aptamer for ocular vascular disease". Nature Reviews. Drug Discovery. 5 (2): 123–32. doi:10.1038/nrd1955. PMID 16518379. S2CID 8833436.
- Savory N, Abe K, Sode K, Ikebukuro K (December 2010). "Selection of DNA aptamer against prostate specific antigen using a genetic algorithm and application to sensing". Biosensors & Bioelectronics. 26 (4): 1386–91. doi:10.1016/j.bios.2010.07.057. PMID 20692149.
- Jeong S, Han SR, Lee YJ, Lee SW (March 2010). "Selection of RNA aptamers specific to active prostate-specific antigen". Biotechnology Letters. 32 (3): 379–85. doi:10.1007/s10529-009-0168-1. PMID 19943183. S2CID 22201181.
- Walsh R, DeRosa MC (October 2009). "Retention of function in the DNA homolog of the RNA dopamine aptamer". Biochemical and Biophysical Research Communications. 388 (4): 732–35. doi:10.1016/j.bbrc.2009.08.084. PMID 19699181.
- Salamanca HH, Antonyak MA, Cerione RA, Shi H, Lis JT (2014). "Inhibiting heat shock factor 1 in human cancer cells with a potent RNA aptamer". PLOS ONE. 9 (5): e96330. Bibcode:2014PLoSO...996330S. doi:10.1371/journal.pone.0096330. PMC 4011729. PMID 24800749.
- "Aptamers NeoVentures Biotechnology". www.neoventures.ca. Retrieved 2016-02-03.
- Kimoto M, Kawai R, Mitsui T, Yokoyama S, Hirao I (February 2009). "An unnatural base pair system for efficient PCR amplification and functionalization of DNA molecules". Nucleic Acids Research. 37 (2): e14. doi:10.1093/nar/gkn956. PMC 2632903. PMID 19073696.
- Yamashige R, Kimoto M, Takezawa Y, Sato A, Mitsui T, Yokoyama S, Hirao I (March 2012). "Highly specific unnatural base pair systems as a third base pair for PCR amplification". Nucleic Acids Research. 40 (6): 2793–806. doi:10.1093/nar/gkr1068. PMC 3315302. PMID 22121213.
- Kimoto M, Yamashige R, Matsunaga K, Yokoyama S, Hirao I (May 2013). "Generation of high-affinity DNA aptamers using an expanded genetic alphabet". Nature Biotechnology. 31 (5): 453–57. doi:10.1038/nbt.2556. PMID 23563318. S2CID 23329867.
- "Accelerating rapid diagnostic development with Optimer™ reagents". YouTube. Aptamer Group. Archived from the original on 2021-12-13. Retrieved 2021-08-09.
- Maugi R, Gamble B, Bunka D, Platt M (April 2021). "A simple displacement aptamer assay on resistive pulse sensor for small molecule detection". Talanta. 225: 122068. doi:10.1016/j.talanta.2020.122068. PMID 33592786. S2CID 231945556.
- Puscasu A, Zanchetta M, Posocco B, Bunka D, Tartaggia S, Toffoli G (February 2021). "Development and validation of a selective SPR aptasensor for the detection of anticancer drug irinotecan in human plasma samples". Analytical and Bioanalytical Chemistry. 413 (4): 1225–36. doi:10.1007/s00216-020-03087-5. PMID 33404749. S2CID 230782101.
- Tartaggia S, Meneghello A, Bellotto O, Poetto AS, Zanchetta M, Posocco B, et al. (March 2021). "An SPR investigation into the therapeutic drug monitoring of the anticancer drug imatinib with selective aptamers operating in human plasma". The Analyst. 146 (5): 1714–24. Bibcode:2021Ana...146.1714T. doi:10.1039/D0AN01860K. ISSN 0003-2654. PMID 33439175. S2CID 230533207.
- Bruno JG (March 2017). "Long Shelf Life of a Lyophilized DNA Aptamer Beacon Assay". Journal of Fluorescence. 27 (2): 439–41. doi:10.1007/s10895-016-2014-x. PMID 28039562. S2CID 34438590.
- "Optimer platform". Aptamer Group. Retrieved 2021-07-11.
- "From aptamer to Optimer". Aptamer Group. Retrieved 2021-07-11.
- "Aptamer Group collaborates with world-leading pharmaceutical company to evaluate Optimer technology". News-medical.net. 28 May 2021. Retrieved 2021-07-11.
- "Aptamer Therapeutics and Cancer Research UK announce partnership for drug development programme". Cancer Research UK. Retrieved 2021-07-11.
- "Aptamer Group collaborates with PinotBio". Contract Pharma. Retrieved 2021-07-11.
- "Aptamer Group and AstraZeneca to explore advanced drug delivery methods". European Pharmaceutical Manufacturer. 5 March 2021. Retrieved 2021-07-11.
- "Aptamer Group and WuXi AppTec collaborate on Optimer therapeutics". Manufacturing Chemist. Retrieved 2021-07-11.
- "Flexible Monitoring of Small Molecules with Aptamer Affinity Reagents Using Bio-Layer Interferometry". YouTube. Aptamer Group. Archived from the original on 2021-12-13. Retrieved 2021-03-01.
- "Aptamer collaborates with Takeda to assess Optimer technology". NS Medical Devices. 31 May 2021. Retrieved 2021-05-31.
- "Aptamer Group, Mologic Ink Deal to Develop Coronavirus Antigen Test". 360Dx. Retrieved 2020-12-02.
- "Aptamer Group and Cytiva to Collaborate on COVID-19 Rapid Test". Insider Media. Retrieved 2020-07-03.
- "Integumen unveils personalised real-time Covid-19 breath test". Shares. Retrieved 2020-09-25.
- "Octet COVID-19 Research". Sartorius. Retrieved 2021-06-26.
- "DeepVerge ready to roll out COVID-19 water contamination system after completing field trials". Proactive Investors. 24 June 2021. Retrieved 2021-06-24.
- Kent AD, Spiropulos NG, Heemstra JM (October 2013). "General approach for engineering small-molecule-binding DNA split aptamers". Analytical Chemistry. 85 (20): 9916–23. doi:10.1021/ac402500n. PMID 24033257.
- Debiais M, Lelievre A, Smietana M, Müller S (April 2020). "Splitting aptamers and nucleic acid enzymes for the development of advanced biosensors". Nucleic Acids Research. 48 (7): 3400–22. doi:10.1093/nar/gkaa132. PMC 7144939. PMID 32112111.
- Colas P, Cohen B, Jessen T, Grishina I, McCoy J, Brent R (April 1996). "Genetic selection of peptide aptamers that recognize and inhibit cyclin-dependent kinase 2". Nature. 380 (6574): 548–50. Bibcode:1996Natur.380..548C. doi:10.1038/380548a0. PMID 8606778. S2CID 4327303.
- Geyer CR, Colman-Lerner A, Brent R (July 1999). ""Mutagenesis" by peptide aptamers identifies genetic network members and pathway connections". Proceedings of the National Academy of Sciences of the United States of America. 96 (15): 8567–72. Bibcode:1999PNAS...96.8567G. doi:10.1073/pnas.96.15.8567. PMC 17557. PMID 10411916.
- Dibenedetto S, Cluet D, Stebe PN, Baumle V, Léault J, Terreux R, et al. (July 2013). "Calcineurin A versus NS5A-TP2/HD domain containing 2: a case study of site-directed low-frequency random mutagenesis for dissecting target specificity of peptide aptamers". Molecular & Cellular Proteomics. 12 (7): 1939–52. doi:10.1074/mcp.M112.024612. PMC 3708177. PMID 23579184.
- Colas P, Cohen B, Ko Ferrigno P, Silver PA, Brent R (December 2000). "Targeted modification and transportation of cellular proteins". Proceedings of the National Academy of Sciences of the United States of America. 97 (25): 13720–25. Bibcode:2000PNAS...9713720C. doi:10.1073/pnas.97.25.13720. PMC 17642. PMID 11106396.
- Shu W, Laurenson S, Knowles TP, Ko Ferrigno P, Seshia AA (October 2008). "Highly specific label-free protein detection from lysed cells using internally referenced microcantilever sensors". Biosensors & Bioelectronics. 24 (2): 233–37. doi:10.1016/j.bios.2008.03.036. PMID 18495468.
- Ko Ferrigno P (June 2016). "Non-antibody protein-based biosensors". Essays in Biochemistry. 60 (1): 19–25. doi:10.1042/EBC20150003. PMC 4986471. PMID 27365032.
- Davis JJ, Tkac J, Humphreys R, Buxton AT, Lee TA, Ko Ferrigno P (May 2009). "Peptide aptamers in label-free protein detection: 2. Chemical optimization and detection of distinct protein isoforms". Analytical Chemistry. 81 (9): 3314–20. doi:10.1021/ac802513n. PMID 19320493.
- Nolan GP (January 2005). "Tadpoles by the tail". Nature Methods. 2 (1): 11–12. doi:10.1038/nmeth0105-11. PMID 15782163. S2CID 1423778.
- Spolar RS, Record MT (February 1994). "Coupling of local folding to site-specific binding of proteins to DNA". Science. 263 (5148): 777–84. Bibcode:1994Sci...263..777S. doi:10.1126/science.8303294. PMID 8303294.
- Reverdatto S, Burz DS, Shekhtman A (2015). "Peptide aptamers: development and applications". Current Topics in Medicinal Chemistry. 15 (12): 1082–101. doi:10.2174/1568026615666150413153143. PMC 4428161. PMID 25866267.
- Bickle MB, Dusserre E, Moncorgé O, Bottin H, Colas P (2006). "Selection and characterization of large collections of peptide aptamers through optimized yeast two-hybrid procedures". Nature Protocols. 1 (3): 1066–91. doi:10.1038/nprot.2006.32. PMID 17406388. S2CID 30644718.
- Škrlec K, Štrukelj B, Berlec A (July 2015). "Non-immunoglobulin scaffolds: a focus on their targets". Trends in Biotechnology. 33 (7): 408–18. doi:10.1016/j.tibtech.2015.03.012. PMID 25931178.
- Huang J, Ru B, Zhu P, Nie F, Yang J, Wang X, et al. (January 2012). "MimoDB 2.0: a mimotope database and beyond". Nucleic Acids Research. 40 (Database issue): D271-7. doi:10.1093/nar/gkr922. PMC 3245166. PMID 22053087.
- "MimoDB: a mimotope database and beyond". immunet.cn. Archived from the original on 2012-11-16. Retrieved 2016-02-03.
- Abeydeera ND, Egli M, Cox N, Mercier K, Conde JN, Pallan PS, et al. (September 2016). "Evoking picomolar binding in RNA by a single phosphorodithioate linkage". Nucleic Acids Research. 44 (17): 8052–64. doi:10.1093/nar/gkw725. PMC 5041495. PMID 27566147.
- Yang X, Dinuka Abeydeera N, Liu FW, Egli M (September 2017). "Origins of the enhanced affinity of RNA-protein interactions triggered by RNA phosphorodithioate backbone modification". Chemical Communications. 53 (76): 10508–11. doi:10.1039/C7CC05722A. PMC 5608642. PMID 28868553.
- Lokesh GL, Wang H, Lam CH, Thiviyanathan V, Ward N, Gorenstein DG, Volk DE (2017). "X-Aptamer Selection and Validation". In Bindewald E, Shapiro BA (eds.). RNA Nanostructures. Methods in Molecular Biology. Vol. 1632. Springer New York. pp. 151–74. doi:10.1007/978-1-4939-7138-1_10. ISBN 9781493971381. PMID 28730438.
- "Raptamer Discovery Group". www.raptamer.com. Retrieved 2021-04-24.
- Wei H, Li B, Li J, Wang E, Dong S (September 2007). "Simple and sensitive aptamer-based colorimetric sensing of protein using unmodified gold nanoparticle probes". Chemical Communications (36): 3735–37. doi:10.1039/B707642H. PMID 17851611.
- Cheng H, Qiu X, Zhao X, Meng W, Huo D, Wei H (March 2016). "Functional Nucleic Acid Probe for Parallel Monitoring K(+) and Protoporphyrin IX in Living Organisms". Analytical Chemistry. 88 (5): 2937–43. doi:10.1021/acs.analchem.5b04936. PMID 26866998.
- Xiang Y, Lu Y (July 2011). "Using personal glucose meters and functional DNA sensors to quantify a variety of analytical targets". Nature Chemistry. 3 (9): 697–703. Bibcode:2011NatCh...3..697X. doi:10.1038/nchem.1092. PMC 3299819. PMID 21860458.
- Agnivo Gosai, Brendan Shin Hau Yeah, Marit Nilsen-Hamilton, Pranav Shrotriya, "Label free thrombin detection in presence of high concentration of albumin using an aptamer-functionalized nanoporous membrane", Biosensors and Bioelectronics, Volume 126, 2019, pp. 88–95, ISSN 0956-5663, doi:10.1016/j.bios.2018.10.010.
- Amero, Paola; Khatua, Soumen; Rodriguez-Aguayo, Cristian; Lopez-Berestein, Gabriel (October 2020). "Aptamers: Novel Therapeutics and Potential Role in Neuro-Oncology". Cancers. 12 (10): 2889. doi:10.3390/cancers12102889. PMC 7600320. PMID 33050158.
- Fattal, Elias; Hillaireau, Hervé; Ismail, Said I. (September 2018). "Aptamers in Therapeutics and Drug Delivery". Advanced Drug Delivery Reviews. 134: 1–2. doi:10.1016/j.addr.2018.11.001. ISSN 1872-8294. PMID 30442313. S2CID 53562925.
- Hafner M, Vianini E, Albertoni B, Marchetti L, Grüne I, Gloeckner C, Famulok M (2008). "Displacement of protein-bound aptamers with small molecules screened by fluorescence polarization". Nature Protocols. 3 (4): 579–87. doi:10.1038/nprot.2008.15. PMID 18388939. S2CID 4997899.
- Huang, Zike; Qiu, Liping; Zhang, Tao; Tan, Weihong (2021-02-03). "Integrating DNA Nanotechnology with Aptamers for Biological and Biomedical Applications". Matter. 4 (2): 461–489. doi:10.1016/j.matt.2020.11.002. ISSN 2590-2385. S2CID 234061584.
- Reynaud, Lucile; Bouchet-Spinelli, Aurélie; Raillon, Camille; Buhot, Arnaud (January 2020). "Sensing with Nanopores and Aptamers: A Way Forward". Sensors. 20 (16): 4495. Bibcode:2020Senso..20.4495R. doi:10.3390/s20164495. PMC 7472324. PMID 32796729.
- Keijzer, Jordi F.; Albada, Bauke (2022). "DNA-assisted site-selective protein modification". Biopolymers. 113 (3): e23483. doi:10.1002/bip.23483. ISSN 1097-0282. PMID 34878181. S2CID 244954278.
- Smith, Drew; Collins, Brian D.; Heil, James; Koch, Tad H. (January 2003). "Sensitivity and Specificity of Photoaptamer Probes". Molecular & Cellular Proteomics. 2 (1): 11–18. doi:10.1074/mcp.m200059-mcp200. ISSN 1535-9476. PMID 12601078. S2CID 13406870.
- Vinkenborg, Jan L.; Mayer, Günter; Famulok, Michael (2012-08-02). "Aptamer-Based Affinity Labeling of Proteins". Angewandte Chemie International Edition. 51 (36): 9176–9180. doi:10.1002/anie.201204174. ISSN 1433-7851. PMID 22865679.
- Keijzer, Jordi F.; Firet, Judith; Albada, Bauke (2021). "Site-selective and inducible acylation of thrombin using aptamer-catalyst conjugates". Chemical Communications. 57 (96): 12960–12963. doi:10.1039/d1cc05446e. ISSN 1359-7345. PMID 34792071. S2CID 243998479.
- Kaur H, Shorie M, Sharma M, Ganguli AK, Sabherwal P (December 2017). "Bridged Rebar Graphene functionalized aptasensor for pathogenic E. coli O78:K80:H11 detection". Biosensors & Bioelectronics. 98: 486–93. doi:10.1016/j.bios.2017.07.004. PMID 28728009.
- Asha K, Kumar P, Sanicas M, Meseko CA, Khanna M, Kumar B (December 2018). "Advancements in Nucleic Acid Based Therapeutics against Respiratory Viral Infections". Journal of Clinical Medicine. 8 (1): 6. doi:10.3390/jcm8010006. PMC 6351902. PMID 30577479.
- Schmitz A, Weber A, Bayin M, Breuers S, Fieberg V, Famulok M, Mayer G (April 2021). "A SARS-CoV-2 Spike Binding DNA Aptamer that Inhibits Pseudovirus Infection by an RBD-Independent Mechanism*". Angewandte Chemie. 60 (18): 10279–85. doi:10.1002/anie.202100316. PMC 8251191. PMID 33683787.
- Hirao I, Kimoto M, Lee KH (February 2018). "DNA aptamer generation by ExSELEX using genetic alphabet expansion with a mini-hairpin DNA stabilization method". Biochimie. 145: 15–21. doi:10.1016/j.biochi.2017.09.007. PMID 28916151.
- Soontornworajit B, Zhou J, Shaw MT, Fan TH, Wang Y (March 2010). "Hydrogel functionalization with DNA aptamers for sustained PDGF-BB release". Chemical Communications. 46 (11): 1857–59. doi:10.1039/B924909E. PMID 20198232.
- Battig MR, Soontornworajit B, Wang Y (August 2012). "Programmable release of multiple protein drugs from aptamer-functionalized hydrogels via nucleic acid hybridization". Journal of the American Chemical Society. 134 (30): 12410–13. doi:10.1021/ja305238a. PMID 22816442.
- Stejskalová A, Oliva N, England FJ, Almquist BD (February 2019). "Biologically Inspired, Cell-Selective Release of Aptamer-Trapped Growth Factors by Traction Forces". Advanced Materials. 31 (7): e1806380. doi:10.1002/adma.201806380. PMC 6375388. PMID 30614086.
- Sahara Hot Start PCR Master Mix
- Ellington AD, Szostak JW (August 1990). "In vitro selection of RNA molecules that bind specific ligands". Nature. 346 (6287): 818–22. Bibcode:1990Natur.346..818E. doi:10.1038/346818a0. PMID 1697402. S2CID 4273647.
- Bock LC, Griffin LC, Latham JA, Vermaas EH, Toole JJ (February 1992). "Selection of single-stranded DNA molecules that bind and inhibit human thrombin". Nature. 355 (6360): 564–66. Bibcode:1992Natur.355..564B. doi:10.1038/355564a0. PMID 1741036. S2CID 4349607.
- Hoppe-Seyler F, Butz K (2000). "Peptide aptamers: powerful new tools for molecular medicine". Journal of Molecular Medicine. 78 (8): 426–30. doi:10.1007/s001090000140. PMID 11097111. S2CID 52872561.
- Carothers JM, Oestreich SC, Davis JH, Szostak JW (April 2004). "Informational complexity and functional activity of RNA structures". Journal of the American Chemical Society. 126 (16): 5130–37. doi:10.1021/ja031504a. PMC 5042360. PMID 15099096.
- Cohen BA, Colas P, Brent R (November 1998). "An artificial cell-cycle inhibitor isolated from a combinatorial library". Proceedings of the National Academy of Sciences of the United States of America. 95 (24): 14272–77. Bibcode:1998PNAS...9514272C. doi:10.1073/pnas.95.24.14272. PMC 24363. PMID 9826690.
- Binkowski BF, Miller RA, Belshaw PJ (July 2005). "Ligand-regulated peptides: a general approach for modulating protein-peptide interactions with small molecules". Chemistry & Biology. 12 (7): 847–55. doi:10.1016/j.chembiol.2005.05.021. PMID 16039531.
- Sullenger BA, Gilboa E (July 2002). "Emerging clinical applications of RNA". Nature. 418 (6894): 252–58. Bibcode:2002Natur.418..252S. doi:10.1038/418252a. PMID 12110902. S2CID 4431755.
- Ng EW, Shima DT, Calias P, Cunningham ET, Guyer DR, Adamis AP (February 2006). "Pegaptanib, a targeted anti-VEGF aptamer for ocular vascular disease". Nature Reviews. Drug Discovery. 5 (2): 123–32. doi:10.1038/nrd1955. PMID 16518379. S2CID 8833436.
- Drabovich AP, Berezovski M, Okhonin V, Krylov SN (May 2006). "Selection of smart aptamers by methods of kinetic capillary electrophoresis". Analytical Chemistry. 78 (9): 3171–78. doi:10.1021/ac060144h. PMID 16643010.
- Cho EJ, Lee JW, Ellington, ADCho EJ, Lee JW, Ellington AD (2009). "Applications of aptamers as sensors". Annual Review of Analytical Chemistry. 2 (1): 241–64. Bibcode:2009ARAC....2..241C. doi:10.1146/annurev.anchem.1.031207.112851. PMID 20636061.
- Spill F, Weinstein ZB, Irani Shemirani A, Ho N, Desai D, Zaman MH (October 2016). "Controlling uncertainty in aptamer selection". Proceedings of the National Academy of Sciences of the United States of America. 113 (43): 12076–81. arXiv:1612.08995. Bibcode:2016PNAS..11312076S. doi:10.1073/pnas.1605086113. PMC 5087011. PMID 27790993.