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Label‐Free Electrical Detection of DNA Hybridization on Graphene using Hall Effect Measurements: Revisiting the Sensing Mechanism
Author(s) -
Lin ChengTe,
Loan Phan Thi Kim,
Chen TzuYin,
Liu KengKu,
Chen ChangHsiao,
Wei KungHwa,
Li LainJong
Publication year - 2013
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201202672
Subject(s) - graphene , materials science , van der pauw method , nanotechnology , oxide , doping , electrolyte , debye length , biosensor , graphene nanoribbons , chemical physics , hall effect , optoelectronics , electrical resistivity and conductivity , electrode , ion , chemistry , engineering , organic chemistry , electrical engineering , metallurgy
There is broad interest in using graphene or graphene oxide sheets as a transducer for label‐free and selective electrical detection of biomolecules such as DNA. However, it is still not well explored how the DNA molecules interact with and influence the properties of graphene during the detection. Here, Hall effect measurements based on the Van der Pauw method are used to perform single‐base sequence selective detection of DNA on graphene sheets, which are prepared by chemical vapor deposition. The sheet resistance increases and the mobility decreases with the addition of either complementary or one‐base mismatched DNA to the graphene device. The hole carrier concentration of the graphene devices increases significantly with the addition of complementary DNA but it is less affected by the one‐base mismatched DNA. It is concluded that the increase in hole carrier density, indicating p‐doping to graphene, is better correlated with the DNA hybridization compared to the commonly used parameters such as conductivity change. The different electrical observations of p‐doping from Hall effect measurements and n‐doping from electrolyte‐gated transistors can be explained by the characteristic morphology of partially hybridized DNA on graphene and the mismatch between DNA chain length and Debye length in electrolytes.