摘要
Atomic layers are sought after for molecular sensing due to their available high surface interaction area,and different types of monolayers are attempted for sensing in the recent past.However,their chemical stability towards these molecules is questioned in recent times and alternate methods need to be developed to circumvent such issues,while maintaining high sensitivity.Here,the van der Waals(vdWs)stacks of molybdenum disulfide(MoS_(2))and graphene are shown for their stable electrochemical sensing towards ascorbic acid(AA)and dopamine(DA)-two important biomolecules.AA is known to chemically react with MoS_(2) leading to unstable sensing platform,while here the graphene coverage is shown to protect the MoS_(2) even from low-energy plasma exposure while keeping the same high sensitivity.Upon proving the graphene-based protection of the sensor,such a sensing platform is shown for its applicability in DA sensing,where it is found to give a linear response in a wide range of concentrations(2.5 to 600μmol·L^(−1))and even selective sensing in the presence of AA.Such a stack is found to be not merely giving protection to the beneath MoS_(2) layer but also the inter-layer charge transfer due to work function differences being beneficial in bringing fast and high sensitivity to the next-generation sensors and point-of-care devices.
基金
This work was financially supported by Department of Science and Technology,India extramural research grant(Grant No.EMR/2017/000513)
intramural grants at TIFR Hyderabad from the Department of Atomic Energy(DAE).
