DNA Gating effect from single layer graphene
- PDF / 237,624 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 37 Downloads / 232 Views
DNA Gating effect from single layer graphene Jian Lin1,2, Desalegne Teweldebrhan2, Khalid Ashraf2, Guanxiong Liu2, Xiaoye Jing,2 Zhong Yan2, Mihrimah Ozkan2, Roger K. Lake2, Alexander A. Balandin2,3, Cengiz S. Ozkan1,3 1
Department of Mechanical engineering, 2 Department of Electrical engineering, 3 Department of Material science and engineering, University of California at Riverside, Riverside, CA 92521, U.S.A. ABSTRACT In this letter, single stranded Deoxyribonucleic Acids (ssDNA) are found to act as negative potential gating agents that increase the hole density in single layer graphene (SLG). Currentvoltage measurement of the hybrid ssDNA/graphene system indicates a shift in the Dirac point and “intrinsic” conductance after ssDNA is patterned. The effect of ssDNA is to increase the hole density in the graphene layer, which is calculated to be on the order of 1.8×1012 cm-2. This increased density is consistent with the Raman frequency shifts in the G-peak and 2D band positions and the corresponding changes in the G-peak full-width half maximum. This patterning of DNA on graphene layers could provide new avenues to modulate their electrical properties and for novel electronic devices. INTRODUCTION Since isolated in 2004[1], graphene emerged as a potential material for fabricating nanoelectronics beyond CMOS. Deoxyribonucleic acid (DNA) and peptide nucleic acids (PNAs) which have base sequences that offer specificity are attractive assembly linkers for bottom-up nanofabrication. Engineered ssDNA sequences are employed in the nanoarchitectures of endfunctionalized single walled carbon nanotubes for device applications including resonant tunneling diodes, field effect transistors and biochemical sensors [2-4]. A thorough understanding of electrical transport through the interface between biological molecules such as DNA and graphene layers is still in its infancy[5]. In this work, we investigate the modulation of carrier transport through graphene layers with overlaying ssDNA fragments via electrostatic interaction. We discovered that the role of ssDNA on the surface of graphene is analogous to applying a negative gate potential in conventional silicon CMOS architectures. Raman spectroscopy has been used in monitoring the doping of graphene layers [6-8]. EXPERIMENT The graphene samples used in this study were extracted from highly oriented pyrolitic graphite (HOPG) slabs via mechanical exfoliation. The graphene samples were deposited on ptype degenerately doped Si (100) wafers (p++) covered with 300nm thick thermally grown SiO2. For device fabrication, we patterned source and drain contacts using electron beam lithography followed by the deposition of source and drain metal consisting of 10nm thick Cr and 100nm thick Au layers (Temescal BJD-1800 electron beam evaporator).
107
The ssDNA sequence employed in this work is CGGGAGCTCAGCGGATAGGTGGGC. The engineered oligonucleotides (Sigma Genosys) were diluted in distilled water to obtain the stock solution. Concentration of the ssDNA solution was calculated to be 28.8
Data Loading...
