| Olle of the lnajor purposes in the field of biochemistry, molecular biology and cellbiology is to study the interactions of two molecules in cells. Each protein has its ownspecific function, bul its function is exerted only when it reacts or inieracts with other' molecules in the living cells. It is essential to analyze the interaction of a protein withanother moIecule. An interaction in living cells is generally at a dynamic equilibrium andnot at a stable equilibrium. That means the reaction of one molecule occurs continuouslyand successively with other molecules. Thus, it becomes an importam issue to observe,measul'e and analyze the biological reactions within the living organism as transient anddynamic reaction. That is the reason why real-time analysis is required in the field ofbiology. Until recently, it has been quite difficult to analyze each reaction on a real-timebasis using currently available biochemical or biophysical methods. Various methodshave been developed to measure the interactions of two molecules, but many of thosemethodologies are not generally suitable for the real-time analysis of molecularinteractions.The technology of surface plasmon resonance (SPR) is a novel sensing methodologyas a key principle fOr the measurement of the interaction of two molecules. SPR is aphysical phenomenon of total intemal reflection (TIR) of light at the interface betweentwo media when a light beam propagates across such an interface from higher refractiveindex media to the lower. SPR is sensitive to the refractive index of the surface medium.The physical characteristic of SPR has been applied to chemo/biosensing in the chemistryand biology. The most importat characteristics of SPR sensors are its caPability in real-time monitoring the reaction of biomolecules on the surface of the sensor without theneed of labeling and purification. The sensing technology of SPR is especially suitablefOr the determination of inieractions between biological molecules. This methodologyand its aPplication are really epoch-making because it has made it possible to measure theinteraction of tWo molecules on a real-time basis.Piezoelectric sensors, commonly known as quartz crystal microbalance, are sensitiveto multiple signals such as the surface mass and the viscosity, density, dielectric effect,conductivity of the liquid. Having many advantages such as real-time analysis, sensitivity,economically, simplicity and digitize, the piezoelectric sensors are suitable for theanalysis of the protCins with high molecular weight.Hepatitis B virus is the most prevalent of all the viral hepatitis agents that can causedeath or significant debilitation. Detection of Hepatitis B surface antigen (HBsAg) inserum is one of important task fOr diagnostics of type B viral hepatitis. To provide a newsensitive and rapid method for diagnostic, we apply the sensing technology of SPR andpiezoelectric to detection of HBsAg. It is the main objective in this thesis.This thesis mainly finished two research tasks: (a) A spectral SPR sensor has beendeveloped to detect HBsAg, (b) A piezoelectric immunosensor has been developed todctect I IBsAg.In tl1e first task, the theory of the sensing technology of SPR is investigated at first. ASPR sensor on the basis of fixing the angle of incident light and measuring the change of'resol1ant wavelength has been designed and installed. lt is aPplied to determined glycerin,ethanol and glucose without any modification. It is also aPplied to determine hepatitis Bsurface antigen using the sensor chip inunobilized with anti-HBsAg monoclonal anibody.To comPare with SPR methOd, the same HBsAg solotions are determined using themethod of enzyme-linked immuosorbent assay (ELlSA). The kinatics of inununo-reaction is studied using the SPR sensoL In the second task, the theory of the sensingtechnology is investigated. A piezoeleCtfic has been developed to detect HBsAg in liquid.The contents of th... |
PDF Full Text Request