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A Quartz Crystal Microbalance DNA Sensor Constructed Based On Enzymatic Amplification Cycle

Posted on:2015-10-23Degree:MasterType:Thesis
Country:ChinaCandidate:Z ZhuFull Text:PDF
GTID:2298330467954801Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
Biological molecules are important components of organisms, which are mainlydivided into biological macromolecules and biological small molecules. The biologicalmacromolecules are proteins, nucleic acids (DNA, RNA), polysaccharides and so on,while biological small molecules are ATP, hormones, neurotransmitters,monosaccharide and lipids. Biomoleculars have effects in the process of metabolism,such as supplying of energy and materials of life, transfering information, controllingembryonic differentiation, promoting growth and development and producing immunefunction. Therefore, the study of highly sensitive dectecting biological molecules areforever core subject in the life sciences. This paper mainly discuss for three aspectsthrough quartz crystal microbalance: Firstly, detecting ATP by quartz crystalmicrobalance throuth gold nanoparticles combined cycle enzyme amplification.Secondly, detecting lysozyme by rolling circle amplification. Thirdly, detecting targetDNA based on building a chain reaction sensor. The major aspects of the article areintroduced as follows:1. Detection of ATP based on enzyme signal amplification cycle quartz crystalmicrobalanceAdenosine triphosphate (ATP) is the essential material of the cells life activities,which is the direct energy source of all life activities. Therefore, the detection of cellATP levels is of great importance. We designed gold nanoparticles bound enzymeamplification loop DNA sensor by quartz crystal microbalance. We immobilizeaptamer on beads,through the specific binding of the aptamer and target ATP. Thestrand displacement polymerization reaction will release sites, which will generate alarge number of single-stranded DNA with the action of tool enzymes. When barcodeis captured onto the modified chip, we can detect ATP by means of the changes of thesignal.2. Detection of lysozyme based on rolling circle amplification quartz crystal microbalanceThe enzyme lysozyme is one kind of alkaline enzymes, which can destroy cellwall then make it dissolved. It can charge protein binding, so it has effect ofanti-bacterial and anti-virus. Therefore detecting the content of lysozyme in the cellhas important significance. We achieve the goal of detecting lysozyme based onCombined with rolling circle amplification and strand displacement amplificationtechnology polymerization through QCM. In the beginning, the aptamer is modified toto the quartz crystal chip, then the aptamer binding to lysozyme will releasesingle-stranded DNA. With the polymerization reaction by polymerase, the chainsubstitution lock will release DNA strand. Rolling circle replication reaction goes onunder the polymerase. Adding in the probe rolling circle long strand improvesdetection signal, then realizing detection of lysozyme.3. Detection of DNA hybridization chain reaction based on quartz crystalmicrobalanceHigh selectivity and sensitivity detection of DNA is very important in clinicaldiagnostics, environmental monitoring and biological defense. In this experiment, wedesign a new method for detecting DNA by quartz crystal microbalance: the hairpinDNA is fixed on the chip surface, which complementary hybridizes with the targetDNA. When the issuer open and complementary hybridizes with DNA, the chainreaction initiator, and then we can detect the content of target DNA.
Keywords/Search Tags:quartz crystal microbalance, adenosine triphosphate lysozyme, rolling circle amplification technology, hybridization chain reaction
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