**3. Conclusion**

Biosensors are low cost analyzers with high potential to be miniaturized. They also provide short measurement time. Thanks to the numerous combinations of biorecognition receptor and transducers, biosensor systems can easily be adapted for the measurement of any kind of analyte. The biological activity of the biorecognition agent on the transducer is the critical element in a biosensor. Biomolecules with low probability of denaturation, adaptable to all kinds of measurements and strong electrical components should be selected for biosensor development. Nucleic acids meet the needs of biosensors at this point. They are advantageous biomolecules that can interact from metal ions to large proteins thanks to their multiple negative charges. Nucleic acids also have the potential to facilitate the determination of organic molecules, such as drugs and pesticides, which can enter between nucleic acid chains thanks to the electroactive guanine base in their structure. They can be used as simple biorecognition agents, similar to an unlimited antibody-antigen interaction, with the potential to be designed to synthetically show affinity for the target molecule. Another important feature of nucleic acids is the potential of their end portions to be modified by secondary signal transmitters without causing any deactivation. Apart from being both a biorecognition agent and an analyte molecule, their immobilization capacity also increases their usage and advantages. In conclusion, the fact that they can be used as a material which provides stability and ease of modification for analysis in biosensor systems puts nucleic acids one step further among other biorecognition agents.
