| The key section of series piezoelectric quartz crystal (SPQC) was composed ofan AT cut,9MHz piezoelectric quartz crystal with a pair of parallel-plate electrodesin series. It has sensitive response to the electric parameter changes (such asconductance and capacitance) between the electrodes. The multi-channel seriespiezoelectric quartz crystal (MSPQC), which was designed based on the principle ofseries piezoelectric quartz crystal, can detect multi-samples at one time. The MSPQCmethod has attracted many analysts because of its high sensitivity, broad sensingspectrum, low cost and easy operation. It has been widely used in a lot of areas, suchas analytical chemistry, life science, clinical medicine，environmental monitoring etc.This dissertation is devoted to the study of novel microorganism piezoelectric quartzcrystal sensors. Based on the non-mass response of MSPQC sensor and metabolismcharacteristics of microorganism, some new detection methods were presented in thisthsis. These new methods were simple, accurate and rapid, which have also broadenedthe application of MSPQC in clinical detection and life science. The main work of thisthesis could be summarized as follows:1. Infection diseases caused by methicillin resistant Staphylococcus aureus(MRSA) have become a big threaten to public health for its untreatable by currentlyavailable antibiotics. A new method for rapid detection of MRSA based onmultichannel series piezoelectric quartz crystal was proposed in this paper. Theimproved YC broth was proposed as the culture medium. Cefoxitin was added into thebroth to distinguish MRSA from methicillin sensitive Staphylococcus aureus (MSSA).A total of51clinical S. aureus isolates were determined by proposed method.Compared with disk diffusion method and VITEK2-compact automated system, theproposed method showed high specificity (98.7%) and sensitivity (100%). In addition,the time needed for MRSA detection by our method was6-8h, which was10hoursshorter than the conventional disk diffusion method. These properties demonstratedthat the MSPQC method could be a simple, rapid and accurate method for routineclinical detection of MRSA.2. An improved YC medium was proposed for rapid detection of CoagulaseNegative Staphylococcus (CNS) by MSPQC in thesis. The new mudium was modifiedby using sucrose instead of glucose.9kinds of clinical CNS were detected by MSPQC method using this improved medium. The results showed that all those9kind clinicalisolates grow well in this new medium. Compared with YC broth, the response signalwas more sensitive in the proposed mudium produced by CNS.9kinds of CNS canalao be deteted in simulating clinical blood samples effectively. The proposedmudium raise the accuracy of CNS detection, which could be popularized in clinicalmicrobiology laboratories.3. A new interdigital electrode-series piezoelectric quartz crystal (IDE-SPQC)sensor for rapid detection of Mycobacterium was proposed. Mycobacteriumsmegmatis were took as a model in the experiment, which has similar structuralfeatures with Mycobacterium tuberculosis but non-pathogenic. In this paper, ConAwere modified on the surface of IDE. Because of the lectin agglutination betweenConA and mannose-containing macromolecules (ManLAM) in the cell envelope of M.smegmatis, M. smegmatis were adsorption on the surface of IDE, which will causeobvious impedance change of IDE. This change can be sensitively monitored bySPQC and the purpose of rapid detection of Mycobacterium can be realized. Thedetection range was1×10~4-1×10~8cfu/ml and the detection time was about30min. |
