應用具互補式金氧半感測晶片之生醫感測系統於三酸甘油脂檢測

Abstract

本研究探討應用具互補式金氧半感測晶片之生醫感測系統於三酸甘油脂檢測。由於代謝症候群已成為常見的文明病之一，而血液中的三酸甘油脂含量又是臨床檢測代謝症候群的重要指標，故三酸甘油脂之生醫檢測系統已成為近代醫療科技發展的趨勢之一。三酸甘油脂透過一系列之酵素反應後可生成紫色之醌亞胺(quinoneimine dye)，對於綠光之吸收度和三酸甘油脂濃度呈正相關，適合以吸光光度法檢測。本生醫感測系統即透過光電二極體將光學訊號轉成電流訊號，並以轉阻放大器將之轉換成電壓訊號，進而達到偵測發光二極體放射之綠光因醌亞胺吸收而產生的光強度差異。此一系統核心晶片結合前述之光電二極體和轉阻放大器，另有一外接回饋電阻，可調整電路放大倍率。該晶片相容於互補式金氧半導體製程，具有體積小、成本低及可大量製造等特性，使用方便且易於普及。實驗結果顯示，此生醫感測系統在0.1 – 2.5 mg/mL範圍內能定量血清樣本中三酸甘油脂之濃度，同時證實ABTS/H2O2/HRP反應可應用於三酸甘油脂於全血樣本中的檢測，能定量三酸甘油脂稀釋後濃度小於7.3 μg/mL的全血樣本，符合臨床檢驗需求。

In this research, the detection of triglyceride using a biosensing system with a CMOS sensor chip is investigated. In the past few decades, metabolic syndrome has become more and more common in the developed countries. Since triglyceride is one of the key traits to determine metabolic syndrome in the clinical diagnosis, to develop a triglyceride-detecting biosensing system has become a trend in the health care industry. While the absorbance of the green light passing through the purple quinoneimine dye, which is produced after a series of biochemical reactions involving enzymatic hydrolysis of the triglyceride, is proportional to the concentration of triglyceride, the absorption photometry is adopted in this study. A photodiode in the biosensing system converts the optical signal to the current signal first, and the a transimpedance amplifier (TIA) converts it to the voltage signal, such that the absorbance of the green light emitted from an LED can be detected. A CMOS sensor biochip integrated the photodiode and the TIA with an external feedback resistor to adjust the sensitivity. The CMOS chip makes the biosensing system portable, inexpensive, and easy-to-use. In summary, the experimental results have shown that the biosensing system can be applied to detect the concentration of triglyceride in serum samples within the range of 0.1 – 2.5 mg/mL. The ABTS/H2O2/HRP reaction was also adopted to detect the triglyceride concentration below 7.3 μg/mL in a diluted whole blood sample. Both of methods are suitable for the clinical diagnosis.