Background: For more than three decades, antibodies were recognized as the most common class of diagnostic molecules with a wide range of applications, until aptamers became as widespread as antibodies. Because of aptamers were able to overcome the weakness of antibodies, so they are a proper substitute for antibodies. These molecules usually are prepared in vitro by combinatorial chemistry techniques which are gradually separated from combined libraries by a laboratory process called SELEX. SELEX round was achieved through repeated consecutive steps that include selection process (binding, separation, and washing), proliferation, and conditioning.

Materials and methods: This case study is a review on the aptamers and comparing them with antibodies and also their application as recognition agent.

Results: Due to the high stability and high affinity of aptamers, they are used as biosensor in diagnosis and treatment, laboratory diagnostic kits, diagnostic approaches in the bioterrorism, and drug delivery.

Conclusion: Applications and capabilities of aptamers and aptasensors showed the importance of research and study of them in different fields of science, specially related to military services such as identifying remaining of chemical weapons, identifying the agent used in bioterrorism, biological threats, viruses, toxins, and pathogens.