Comparison of Graphene Oxide and Reduced Graphene Oxide for DNA Adsorption and Sensing.
Fluorescently labeled DNA adsorbed on graphene oxide (GO) is a well-established sensing platform for detecting a diverse range of analytes. GO is a loosely defined material and its oxygen content may vary depending on the condition of preparation. Sometimes, a further reduction step is intentionally performed to decrease the oxygen content, and the resulting material is called reduced GO (rGO). In this study, DNA adsorption and desorption from GO and rGO is systematically compared. Under the same salt concentration, DNA adsorbs slightly faster with a 2.6-fold higher capacity on rGO. At the same time, DNA adsorbed on rGO is more resistant to desorption induced by temperature, pH, urea, and organic solvents. Various lengths and sequences of DNA probes have been tested. When its complementary DNA is added as a model target analyte, the rGO sample has a higher signal-to-background and signal-to-noise ratio, whereas the GO sample has a slightly higher absolute signal increase and faster signaling kinetics. DNAs adsorbed on GO or rGO are still susceptible to nonspecific displacement by other DNA and proteins. Overall, although rGO adsorbs DNA more tightly, it allows efficient DNA sensing with an extremely low background fluorescence signal.
College of Biosystems Engineering and Food Science, Zhejiang University , Hangzhou 310058, China.|Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada.
Chang
C
Lu
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada.
Po-Jung Jimmy
PJ
Huang
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada.
Biwu
B
Liu
College of Biosystems Engineering and Food Science, Zhejiang University , Hangzhou 310058, China.
Yibin
Y
Ying
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo N2L 3G1, Ontario, Canada.
Juewen
J
Liu