DNA in nanopores: negative capacitance and delta-relaxation at high frequency.
We measured the high frequency dielectric relaxation behavior of DNA molecules confined in nanopores of polycarbonate membrane. The data revealed the existence of a critical frequency omega(c) approximately GHz at which the ac conductivity showed delta-relaxation. Interestingly, the DNA molecules also exhibited a crossover from positive to negative capacitance corresponding to omega(c). The negative capacitance at the critical frequency suggested a strong inductive behavior of DNA molecules in the high frequency regime. The results are interpreted in terms of the confined geometry of the DNA molecules in the nanopores. The interfacial water H-bonded to DNA played a crucial role in determining the high frequency relaxation of DNA molecules. The results indicated that the DNA in nanopores could be designed for application in high frequency bandpass/notch filters.
Mandal
S K
SK
Department of Physics, Visva-Bharati, Santiniketan 731235, India.
D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D025802:Electric Capacitance; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D016062:Porosity; D012666:Semiconductors; D013499:Surface Properties
D004247:DNA