Peculiarities of DNA detection using evanescent field biosensing

It is shown that the main peculiarities of DNA biosensing are related with electrical charge of nucleic acid molecule. The electrostatic interaction plays an important role in specificity of the sensor and can be the reason of strong steric hindrance for high length DNA fragments in negatively charged three dimensional matrix known as powerful tool for detection of proteins. Therefore, the design of recognition element for rather long products of polymerase chain reaction (PCR) needs its own strategy different from one optimized for proteins.