| The phenol compound is a kind of environmental pollutants. It’s necessary to construct a new phenol sensor with high sensitivity and stability and excellent reproducibility for the determination of phenol compounds. Among the detection methods of phenolic substances, electrochemical method has the advantages of low cost, simple operation, high sensitivity and good selectivity. Modified materials and modification method for the construction of the electrochemical modified electrode are very important to the performance of the modified electrode. Particularly, nanomaterials are widely used to modify the electrode due to their attractive electronic, chemical and mechanical properties. In this paper, nanocomposite motified electrodes were proposed for the simultaneous determination of phenols. The result shows that the proposed sensors have high sensitivity, selectivity, low limit of detection for the determination of phenol compounds. The main works are as follows:(1) Multi-walled carbon nanotubes and poly(2-acetyl-5-bromothiophene) modified electrode for the simultaneous determination of catechol, hydroquinone and p-cresolMulti-walled carbon nanotubes (MWCNTs) and poly(2-acetyl-5-bromothiophene) were used to modify glassy carbon electrode for the simultaneous determination of hydroquinone (HQ), catechol (CC), and p-cresol (PC). The modified electrode was characterized by differential pulse voltammetric (DPV), cyclic voltammetry (CV) and transmission electron microscope (TEM). The modified electrode showed a high sensibility and selectivity to the determination of HQ-, CC and PC with the linear ranges of1.0×10-5～8.0×10-4mol/L,5.0×10-6～5.5×10-4mol/L and5.0×10-6-7.5×10-4mol/L, respectively. The detection limits were3.0×10-6mol/L,1.7×10-6mol/L and2.0×10-6mol/L, respectively.(2) Nano-Au and overoxidized-polydopamine film modified electrode for the the simultaneous determination of catechol, hydroquinone and p-cresol A novel sensor was constructed by electrodepositing nano-Au on overoxidized-polydopamine film (PDAox) modified glassy carbon electrode (GCE). Due to the excellent electrochemical catalytic activities and high surface area of the nano-Au/PDAox/GCE, the sensor exhibited high sensitivity and good selectivity and stability for hydroquinone (HQ), catechol (CC) and p-cresol (PC). Scanning electron microscopy (SEM), cyclic voltammetry (CV) and different pulse voltammetry (DPV) were employed to characterize the sensor. The calibration curves for HQ, CC and PC were obtained in the ranges of1.0×10-5～5.5×10-4mol/L,1.Ox10-6～6.0×10-4mol/L and1.0×10-6～3.0×10-4mol/L with detection limits (S/N=3) of3.0×10’7mol/L,1.7×10-6mol/L and3.0×10-7mol/L, respectively. More importance, the proposed method provides a promise for simple, rapid and cost-effective analysis of environmental pollutants.(3) The magnetic core-shel microspheres-multiwal carbon nanotubes nanocomposites modified electrode for the simultaneous determination of catechol and hydroquinoneA new type of phenolic sensor was proposed for the simultaneous determination of hydroquinone (HQ) and catechol (CC). Firstly, multiwalled carbon nanotubes (MWCNTs) were modified on the surface of a glassy carbon electrode (GCE). Then, the first layer of tyrosinase (Tyr) was assembled onto it. Subsequently, magnetic core-shell microspheres (Fe3O4@SiO2-Au@mSiO2) were modified onto the electrode to immobilize the second layer of Tyr. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements were carried out to detect hydroquinone (HQ) and catechol (CC) with the target sensor. Scanning electron microscope (SEM) was employed to characterize the microstructure of the synthesized Fe3O4@SiO2-Au@mSiO2. Simultaneous detections of the two environmental contaminations (HQ and CC) were accomplished by employing the target electrode with the linear ranges of5.0×10-6～1.8×10-3mol/L and2.0×10-6-8.4×10-4mol/L, respectively. And the detection limits were1.7×10-6mol/L for HQ and6.7×10-7mol/L for CC. |
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