Electrochemical Research On Persistent Organic Pollutants

Persistent Organic Pollutants （POPs） are a kind of synthetic chemicals, which arepersistent in the environment, accumulated through biological food chain and poseharmful effect to human health. They have four characteristics: highly toxic, persistent,bioaccumulative and lipophilic hydrophobic. Human being who are at the top of thefood chain can put these toxic enlarged to seven times. The harm of Persistent OrganicPollutants （POPs） is the reason why the government of every country, administrationsection, academic circle, industry and agriculture, and the public widely pay closeattention to them. And now, POPs have become one of worldwide environmentalproblem which have much attention. How to develop a fast, accurate and sensitivedetection method of POPs in daily necessities, cosmetics, food and the environment,quickly become a new challenge for the analysis of POPs in analytical chemistry andenvironmental testing.This thesis selected pentachlorophenol （PCP）, Octachlorostyrene （OCS）as theresearch objects, and designed three types of methods based on nanomaterials forquick scanning of POPs. Utilizeing the electrochemical methods with high sensitivity,simple instrumentation, rapid analysis, good controllability, we design three rapidanalysis sensors. This thesis provides new ideas for analysis of pollutants. The maincontents are as follows:（1） Electrogenerated chemiluminescence （ECL） detection of PCP using carbonquantum dots: Carbon quantum dots were fabricated by hydrothermal method andshowed stable and intensive electrogenerated chemiluminescence in the presence of thecoreactant K₂S₂O₈. Under the scanning potential of1.2to0.5V, PCP reacts with theexcited C-, resulting in a decrease in ECL. The detection of trace level PCP is thereforeachieved.This method exhibits good performance for PCP determination comparedwith other methods which had been published. Under the optimal conditions, adetection limit of1.3×10¹²g/L is achieved with a linear range of10pg/L1.0mg/L。（2） Proposed a direct electrochemical method for quick scanning of PCP usingAu/TiO₂/GCE: The modification of TiO₂nanoparticles and Au nanoparticles canimprove the specific surface area and electrical conductivity of GCE, which canincreases the response of the PCP oxidation peak current value. The preparationmethod is simple, reproducible. The linear range is from0.1μM to0.5mM and the detection limit is2.7×10^-8M.（3） Indirectly competitive immuno assay for octachlorostyrene: Aself synthesized OCS antibody was immobilized on the immunosensor by acompetitive immunoreaction in solution, followed by the immobilization of goatanti rabbit IgG HRP. Comparaed with traditional chromatography, mass spectrometrydetection methods, this method has several advantages including low cost, simpleinstrument operation, which can be applied to large quantities assay of samples.Thelinear range is from5nM to1μM, and the detection limit is3.6nM.