Study On Electrochemical Detection Of Drug Molecules Based On Molybdenum Disulfide Nanocomposites

Three-dimensional molybdenum disulfide nanostructure?3D MoS₂?has a large specific surface area,more active sites and can inhibit its aggregation.However,its low conductivity will affect the application in electrochemical sensors.Among many carbon materials,graphene and multi-walled carbon nanotubes?MWCNTs?possess good electrical conductivity,large specific surface area and excellent biocompatibility.Therefore,the composite of MoS₂ and carbon nanomaterials should have better electrochemical performance than one single material,which could effectively improve the sensitivity and selectivity of the prepared electrochemical sensors.Herein,electrochemical sensors were prepared by MoS₂,graphene,MWCNTs and other materials for the detection of drug molecules including epinephrine?EP?and acetaminophen?AC?.The main research contents were divided into the following three parts.?1?An electrochemical sensor based on AuNPs/MoS₂/rGO nanocomposite was constructed for sensitive detection of epinephrine.3D MoS₂?nanospheres?/rGO were prepared by hydrothermal method.AuNPs were deposited on the surface of MoS₂/rGO modified electrode by potentiostatic deposition.It was shown that within the range of 0.5-10 ?M and 10-1000 ?M,there was a good linear relationship between the oxidation peak current value and the logarithmic concentration of EP,and its detection limit is 2 nM.In addition,the sensor possesses high selectivity.?2?MoS₂/MWCNTs nanocomposites were prepared based on multi-walled carbon nanotubes by the use of a hydrothermal method for the determination of EP.The nanocomposite modified electrode has good electrocatalytic ability as well as abundant electroactive sites,and can promote electron transfer on the electrode surface.It is shown a good linear relationship with the concentration of EP in the range of 0.1-10 ?M as well as 10-60 ?M,and the detection limit is 10 nM.Additionally,the sensor also has good stability and reproducibility.It was also applied for the detection of epinephrine in human urine samples by recovery experiments and showed recoveries of 94.7%-109%.?3?In order to further expand the electrochemical performance of the above sensor,poly-L-aspartic acid?P?L-Asp??was electropolymerized onto the synthesized MoS₂/MWCNTs nanocomposite modified electrode and EP as well as AC can be detected simultaneously.The results showed that the logarithmic oxidation peak current of EP and AC showed good linear relationship with the logarithmic concentration of EP and AC in the range of 0.5-50 ?M and 50-1000 ?M,0.5-100 ?M and 100-1000 ?M,respectively.The detection limits are 18 nM and 30 nM,respectively.It was shown that the P?L-Asp?/MoS₂/MWCNTs based electrode has a good electrochemical response to EP and AC,which could be attributed to the large specific surface area of 3D MoS₂/MWCNTs.Due to the synergistic effect of P?L-Asp?,simultaneous detection of EP and AC was realized.This sensor has good anti-interference ability and was employed for the detection of human urine with recoveries of 95.0%-105%.