TY - JOUR
T1 - Covalent functionalization of MoS2nanosheets synthesized by liquid phase exfoliation to construct electrochemical sensors for Cd (II) detection
AU - Gan, Xiaorong
AU - Zhao, Huimin
AU - Wong, Kwok Yin
AU - Lei, Dang Yuan
AU - Zhang, Yaobin
AU - Quan, Xie
PY - 2018/5/15
Y1 - 2018/5/15
N2 - Surface functionalization is an effective strategy in the precise control of electronic surface states of two-dimensional materials for promoting their applications. In this study, based on the strong coordination interaction between the transition-metal centers and N atoms, the surface functionalization of few-layer MoS2nanosheets was successfully prepared by liquid phase exfoliation method in N, N-dimethylformamide (DMF), 1-methyl-2-pyrrolidinone, and formamide. The cytotoxicity of surface-functionalized MoS2nanosheets was for the first time evaluated by the methylthiazolyldiphenyl-tetrazoliumbromide assays. An electrochemical sensor was constructed based on glass carbon electrode (GCE) modified by MoS2nanosheets obtained in DMF, which exhibits relatively higher sensitivity to Cd2+detection and lower cytotoxicity against MCF-7 cells. The mechanisms of surface functionalization and selectively detecting Cd2+were investigated by density functional theory calculations together with various spectroscopic measurements. It was found that surface-functionalized MoS2nanosheets could be generated through Mo-N covalent bonds due to the orbital hybridization between the 5 s orbitals of Mo atoms and the 2p orbitals of N atoms of the solvent molecules. The high selectivity of the sensor is attributed to the coordination reaction between Cd2+and O donor atoms of DMF adsorbed on MoS2nanosheets. The robust anti-interference is ascribed to the strong binding energy of Cd2+and O atoms of DMF. Under the optimum conditions, the electrochemical sensor exhibits highly sensitive and selective assaying of Cd2+with a measured detection limit of 0.2 nM and a linear range from 2 nM to 20 μM.
AB - Surface functionalization is an effective strategy in the precise control of electronic surface states of two-dimensional materials for promoting their applications. In this study, based on the strong coordination interaction between the transition-metal centers and N atoms, the surface functionalization of few-layer MoS2nanosheets was successfully prepared by liquid phase exfoliation method in N, N-dimethylformamide (DMF), 1-methyl-2-pyrrolidinone, and formamide. The cytotoxicity of surface-functionalized MoS2nanosheets was for the first time evaluated by the methylthiazolyldiphenyl-tetrazoliumbromide assays. An electrochemical sensor was constructed based on glass carbon electrode (GCE) modified by MoS2nanosheets obtained in DMF, which exhibits relatively higher sensitivity to Cd2+detection and lower cytotoxicity against MCF-7 cells. The mechanisms of surface functionalization and selectively detecting Cd2+were investigated by density functional theory calculations together with various spectroscopic measurements. It was found that surface-functionalized MoS2nanosheets could be generated through Mo-N covalent bonds due to the orbital hybridization between the 5 s orbitals of Mo atoms and the 2p orbitals of N atoms of the solvent molecules. The high selectivity of the sensor is attributed to the coordination reaction between Cd2+and O donor atoms of DMF adsorbed on MoS2nanosheets. The robust anti-interference is ascribed to the strong binding energy of Cd2+and O atoms of DMF. Under the optimum conditions, the electrochemical sensor exhibits highly sensitive and selective assaying of Cd2+with a measured detection limit of 0.2 nM and a linear range from 2 nM to 20 μM.
KW - Cd2+
KW - Electrochemical sensor
KW - Few-layer MoS2 nanosheets
KW - Liquid
KW - Phase exfoliation
KW - Surface functionalization
UR - http://www.scopus.com/inward/record.url?scp=85042659068&partnerID=8YFLogxK
U2 - 10.1016/j.talanta.2018.01.059
DO - 10.1016/j.talanta.2018.01.059
M3 - Journal article
VL - 182
SP - 38
EP - 48
JO - Talanta
JF - Talanta
SN - 0039-9140
ER -