| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 102 === Abstract
Over the past decades, surface plasmon resonance (SPR) has been utilized in a wide range of chemical and biological sensing applications because of the potential of such sensors for various applications in the health-related market. One important reason that SPR sensors have become a powerful analytical tool with numerous applications is their capability for real-time measurement with high detection sensitivity. They also have the ability to quantitatively detect interactions between biomolecules. Traditional sensing techniques for extracting information from SPR are primarily concerned with analyzing the angular and wavelength properties of the reflected light beam within the resonant reflectance dip. Recently, research attention in SPR sensing has shifted to measuring the SPR phase shift because the phase change behavior exhibits a steep jump, which leads to the potential in achieving extremely high sensitivity.
In Taiwan, one person passed away per hour from diabetes, which is a serious disease for human beings. Blood glucose concentration measuring is the way to tell if one have pre-diabetes or diabetes. A normal glucose level is 110 milligrams per deciliter (mg/dl) or below, a diabetic level is 126 mg/dl or higher, and a pre-diabetes level is between 110 mg/dl and 125 mg/dl. In this thesis, the glucose oxidase (GOD) was utilized for immobilization for higher sensitive glucose sensing.
First of all, the commercial software, matlab, was used to simulate SPR phenomena with various metals and their thickness. In this thesis, the stable metal, gold, was simulated to illustrate the reflection coefficient of 0.0196 and resonance angle of 61.90 with 30-nm thickness at 1550-nm operating wavelength.
Glucose oxidase (GOD) on the prism gold metal surface was immobilized by chemical reaction, MUA, EDC/NHS, and PBS. A SPR phase sensor was developed based on optical low coherence interferometry (OLCI) system with stepping motor to detect the phase shift due to SPR effect and interference effect. For the immobilized glucose GOD experiments, the glucose concentrations with 100 mg/dl, 200 mg/dl, 300 mg/dl, and 400mg/dl were characterized. The experimental results obtained from glucose concentration indicate that the stability of the system is 4.2857 degrees, and the sensitivity are 0.3514 (Degree/(mg/dl)) and 0.5143 (Degree/(mg/dl) before and after immobilization, respectively. We can see that the immobilization of SPR system can improve the measurement sensitivity about one and half times.
For immobilized SPR sensing limit study, the glucose concentrations of 10 mg/dl, 5mg/dl, 1mg/dl, 0.1 mg/dl, 0.05 mg/dl, and 0.01 mg/dl were all analyzed and lowest phase detection limit could be demonstrated on 0.1 mg/dl glucose. The sensitivity and resolution for concentration were (degree/(mg/dl)) and, 3.5486 mg/dl respectively.
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