Detection technique of biotin-streptavidin binding using semiconducting single walled carbon nanotube based on interdigital capacitors

As binding in order biotin and streptavidin onto SWNT, we observed that each resonant frequency of S11 parameter was noticeably changed. This means that the binding between SWNT and biomaterials onto SWNT changes the capacitance value of detection system due to electrical permittivity (epsiv) difference of biotin and streptavidin. As the specific inter-molecules such as a high affinity binding of biotin and streptavidin is bound, we could observe dramatically the resonant frequency shift. This is a great merit of applying biosensor system for detection of inter-molecular binding or self-assembly because we can judge whether binding or unbinding by resonant frequency shift. Therefore, we conclude that the binding detection system of a semiconduting SWNT based on interdigital capacitors has feasibility that can detect the coupling between biotin and streptavidin and also apply this system to a specific inter-biomaterials binding such as antigen and antibody.