Determination Aluminum In Body Fluids And Phenols Pollutants In Environment By The Carbon Nanomaterials Modified Electrodes

Aluminum(Al) is present at relatively high concentration in the earth’s crust, in drinking water and foods such as herbs, tea, barking powders and so on, and is used in antacids for the treatment peptic ulcers and gastritis. Aluminum has long been regarded as a relatively nontoxic element for animals and human beings, but there is now concern over the use of orally dosed aluminum compounds. Aluminum neurotoxicity has been demonstrated in long-term renal dialysis patients, and there is a possible link between the deposition of aluminum in the brain and Alzheimer’s disease (AD), Parkinson’s disease (PD), dialysis dementia. The concentration of aluminum in the brains of AD patients is increased and Al appears to accumulate in specific regions of the brain, neural systems are one of the targets of Al. Researches show that excess exposure to Al could be one of causes of encephalopathy, meanwhile, aluminum overload in dialysis patients and experimental animals can result in anemia and disorders of bone metabolism. Al could also inhibit the immunization system, the growth rate of lymph cells in cultures, and the growth of embryos. Thus, it is important to find a reliable method to measure the trace amount of Al in a human body. In the measurement of trace Al, aroma phenols ligand has been used as the sequestering agent. In the current research, the focus is on the enhancement of the engagement of aroma phenols ligand on electrode. By deliberating choices of graphene, mutil-walled carbon nanotubes and hyprocrellin A(HA) adulterated with graphene, A series of novel electrodes have been designed. Comparing with nude electrode, the new electrodes have predominant unique selection and combination of Al which can guarantee the stability of electrical signal in measurements. The dissertations include:1. Methodology of the manufacture of mutil-walled carbon nanotubes, GO, CRG and adulterated modified electrode and their characterization using TEM, ATR-FTIR, RAMAN were described. A new method which can measure Al in human body liquid has been developed. The new method was based on the study of the absorption of aroma phenols ligand such AR,8-HQ, HA to the new electrodes. The study was carried out using the combination of electric-chemical method, such as EIS, and spectrum. The new method is simple, reliable, and sensitive which can be used in measuring Al in samples directly without pretreatment. The new method provides an new area in designing the next generation of bio-sensor.2. Phenol seriously harms to humans and the environment, therefore, detecting accurately of trace phenol is of great significance. The electric-chemical behavior of phenol on the CS-CRG/GC has been investigated by CV and DPV. Comparing with the GC, GO/GC, we found smaller resistance, higher peak current and negative deposition of peak position in the modified electrode. This modified electrode oxidation reaction is controlled by diffusion, the optimum conditions of measurement are:0.3v for voltage,300s for time, and 7.0 for pH. The scope of measurement of Al is 10-7～10-5mol/L; the low detection limit is 1×10-8mol/L(S/N=3). Finally, this proposed sensor was successfully employed to determine the phenol in real samples and the recoveries were between 100% and 102.0%. Based on the experiments, a new CRG/GC fast method for 1-OHP is proposed. Compared with GC, electrical signals in the CRG/GC were enhanced, due to the absorption effects of graphene.3.1-Hydroxypyrene (1-OHP) is a kind of polycyclic aromatic hydrocarbons (PAHs) metabolites and has been widely used as a biomarker for evaluating human exposure to PAHs. In this paper, an electrochemical sensor was fabricated based on graphene-MN202 modified glass carbon electrodes and used to pre-concentrate and detect 1-OHP. When 1-OHP was pre-concentrated on modified electrodes, the response signals and adsorption stability were enhanced. The electrochemical characteristics of 1-OHP on the modified electrode were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Experimental parameters, such as the adsorption potential, adsorption time, scan rate, and the pH values of buffer solution were optimized. Under the optimized conditions, the peak current was proportional to 1-OHP concentration in a wide range of 0.005 to 12.0 μmol/L, and the detection limit was 1.72nmol/L(S/N=3). Moreover, the fabricated electrode also exhibited good reproducibility and stability, and can be employed to in situ determinate 1-OHP in human urine successfully.