Potential response of genetic field effect transistor to charged nanoparticle-DNA conjugate

In this study, we report the potential response and the improvement of detection sensitivity of genetic FET by introducing the charged nanoparticle-DNA conjugate. When oligonucleotides probes, of which the 5-end was modified with a thiol group, were immobilized on the surface of gold nanoparticles, the nanoparticle-DNA conjugates had the large amount of negative charges in an aqueous solution. The detection sensitivity of genetic FET depends on the amount of charged molecules on the gate surface. Introducing the charged nanoparticle-DNA conjugate into genetic FET, the V_T was shifted to the positive direction by the large amount of 76 mV due to the large negative charges of the charged conjugate. The introduction of the charged nanoparticle-DNA conjugate into genetic FET resulted in the highly sensitive detection of DNA recognition events. Therefore, the highly sensitive DNA analyses are expected using the genetic FET in combination with the charged nanoparticle-DNA conjugate.