Application Of Graphene And Flexible Device In Residue Analysis Of Organophosphorus Pesticide

Graphene, a representative of the typical family of nanomaterials, has the unique propertis of optical, electrical, and mechanical that draw full attention of the scientists. Moreover, high theoretical specific surface area of graphene makes it suitable for the applications in adsorption and detection for pesticides. This research took the eleven organophosphorus pesticides as targets, a new form of graphene-coated silica (GCS) has been prepared for exploring the ability of adsorption for eleven organophosphorus pesticides. According to the good adsorption of graphene for chlorfenvinphos, a flexible device was fabricated and applied to detect the concentration of chlorfenvinphos in water. The main results of this research are as followed:1:This research took silica as a carrier, and then graphene was coatied on silica to prepared GCS. The adsorpt ability of GCS for organophosphate pesticides in water was studied. Optical photographs, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) analysis, and elemental analysis has been used to characterize the GCS. GCS was researched for adorbing the eleven organophosphorus pesticides in water. Several factors including GCS dose, the adsorption time, and pH value of the solution have been optimized in order to obtain the maximum adsorption efficiency. Beside, the adsorption abilities of GCS was compared with five other sorbents (graphite carbons, activated carbon, pure graphene, C18silica, and silica) for the eleven organophosphorus pesticides. The result shows GCS has good adsorption performance and separation ability. The adsorption mechanism has been discussed and proved to be dependent on the electron-donating abilities of the S, P, and N atoms and the strong π-bonding network of the benzene rings.2:A flexible device was fabricated based the electrochemically reduced graphene oxide (ERGO), and it has been used as a sensor to detect the concertration of chlorfenvinphos in water. ERGO has been characterized via Raman spectroscopy, scanning electron microscope (SEM), and atomic force microscopy (AFM). And the detecting effect of flexible device under different concentrations of graphene oxide was compared. The results show the ERGO based flexible device with the concertration of graphen oxide at1mg/L has a good detection of chlorfenvinphos with the concertration from0.001mg/L to100mg/L.