Detection Of Pollutants By Catalytic Chemiluminescence Analysis Of Gold Nanoparticles And Their Complexes

The simple,rapid and highly sensitive detection of the organic contaminant bisphenol A and the pesticide acetamiprid is essential for protecting the environment and preventing human health risks.The organic drug heparin is used as a postoperative anticoagulant drug,and real-time monitoring of its quantity has an important guiding role for clinical medication.In this thesis,using positively charged nano-gold and graphene oxide/nano-gold nanocomposite on the catalytic performance of luminol chemiluminescence reaction,an analytical method for the detection of organic drug heparin,organic pollutant bisphenol A and pesticide acetamiprid was established.The specific research content is as follows:(1)The organic drug heparin is the biomolecule with the highest electronegativity known.To synthesize positively charged nano-gold on the surface,use the interaction between heparin with high negative charge and positively charged nano-gold to shield the positive charge on the surface of positively-charged gold nano-gold,which leads to the weakening of its catalytic performance for the chemiluminescence reaction of luminol.Construct a simple and sensitive chemiluminescence analysis method to detect heparin.When heparin is not present in the system,the positively charged nano-gold catalyzes the chemiluminescence reaction of luminol-hydrogen peroxide to produce a strong chemiluminescence signal;while in the presence of heparin,the interaction between heparin and nano-gold shields the positive charge of the nano-gold surface,Causing it to catalyze the chemiluminescence reaction to produce a very weak luminescence signal.Under the best experimental conditions,the concentration of heparin is in the range of 0.30?16.00 ng/mL,and the logarithm of the concentration is linearly correlated with the intensity of the chemiluminescence signal,and the detection limit is 0.06 ng/mL.And this analysis has high selectivity for heparin detection.The recovery experiment was carried out on the actual samples,and the recovery rate was in the range of 94.6%?105.0%,and the relative standard deviation was less than 4.1%,indicating that the method has certain accuracy for the detection of heparin.In addition,as an antidote to heparin,protamine can detect protamine indirectly by chemiluminescence analysis through the interaction between positively charged protamine and highly negatively charged heparin.The study showed that the concentration of protamine was linearly correlated with the intensity of chemiluminescence signal in the range of 25.00?115.00 ng/mL,and the detection limit was 12.00 ng/mL.The recovery rate of the actual sample addition and recovery experiment is in the range of 95.0%?106.2%,and the relative standard deviation is less than 4.2%.The results show that this method can be used for protamine detection.(2)Aptamers have high specificity for target recognition.Utilizing the completely different interactions between aptamers of different conformations and positively charged gold nanoparticles,the interaction of bisphenol A and bisphenol A aptamers induces conformational changes of the aptamers,which leads to the chemiluminescence of positively charged gold nanoparticles on luminol-silver nitrate The catalytic performance of the system is changed to realize the detection of organic pollutant bisphenol A by chemiluminescence analysis.When there is no bisphenol A in the system,the aptamer is a one-dimensional linear single-stranded DNA structure,which can be easily adsorbed and wrapped on the surface of the positively charged gold nanoparticle,shielding the positive charge of the gold nanoparticle,resulting in a weak catalytic chemiluminescence reaction.When there is bisphenol A in the system,the action of bisphenol A and bisphenol A aptamer causes the aptamer to form a stable three-dimensional structure.The aptamer of this conformation cannot interact with nano-gold,and nano-gold still Maintaining its high positiveness,it catalyzes the chemiluminescence reaction of luminol to produce a strong chemiluminescence signal.Under the best experimental conditions,the intensity of the chemiluminescence signal is linearly correlated with the concentration of bisphenol A in the range of 0.10?40.00 ng/mL,and the detection limit is 6.20×10-2 ng/mL.The research results show that the detection of bisphenol A based on chemiluminescence analysis of aptamer has high selectivity.The recovery rate of the standard addition recovery experiment is in the range of 95.0%?105.3%,and the relative standard deviation is less than 5.1%.The results show that the analysis is accurate and reliable for actual sample detection.(3)Using graphene oxide/nano-gold nanocomposite materials as chemiluminescence signal probes,the use of nanocomposite materials to synergize luminol chemiluminescence reaction with high catalytic performance,combining different conformational aptamers and nanocomposite materials to achieve different interactions Highly sensitive and selective chemiluminescence analysis for the detection of pesticide acetamiprid.When acetamiprid does not exist in the system,the acetamiprid aptamer adsorbs on the surface of the graphene oxide/nano-gold nanocomposite.At this time,the nanocomposite is not easy to contact with chemiluminescent reagents,resulting in a decrease in the local concentration of the analysis system.Weak chemiluminescence signal;when acetamiprid is present in the system,the action of acetamiprid and its aptamer induces the aptamer to form a stable spatially rigid three-dimensional structure.The conformational aptamer is difficult to adsorb on the nanocomposite material,and the nanocomposite The material remains in its original state,and synergistically catalyzes the luminol-hydrogen peroxide chemiluminescence reaction to produce a strong chemiluminescence signal.Under the best experimental conditions,the concentration of acetamiprid was linearly correlated with the intensity of the chemiluminescence signal in the range of 2.10×10-11?9.00×10-9 M,and the detection limit was 8.90 pM.The aptamer-based chemiluminescence analysis to detect the pesticide acetamiprid has high selectivity.The recovery experiment was carried out on the actual samples,and the recovery rate was in the range of 94.0%?103.2%,and the relative standard deviation was less than 4.4%.The results showed that the analysis was accurate and reliable for the detection of pesticide residues in actual samples.