結合光子晶體及介電濕潤技術應用於免標定檢測之實驗室晶片系統開發

Abstract

傳統的免疫分析實驗包含了生物分子的固定、實驗試劑的配置、待測物多種濃度調配、標記、生物分子表面重組（Regenerate）、清洗（Wash）等步驟，繁瑣、重複性高，且需要不同的機台操作，實驗室晶片(Lab-on-a-chip, LOC)將傳統生物實驗須在實驗室完成的步驟整合在晶片上的概念更顯需要。以數位微流體系統作為實驗的操作平台，晶片製程簡單，不須額外加裝驅動幫浦和閥，可為開放式系統避免液珠阻塞現象，液珠的大小可為微米級或奈米級，更能節省化學試品的使用量，且可程式化用電腦自動操控實驗進程，這些優點非常符合生醫研究的需求。在臨床醫學診斷上，疾病的早期篩檢是免疫分析法熱門的研究方向，現行常用的免疫分析方式為螢光標定，但其需要進行標定過程，此過程往往需要數個小時，且有螢光衰減的問題造成及時偵測的困難性。 本研究是要開發一種免標定式生物感測晶片，將以介電濕潤(Electrowetting-on-dielectric, EWOD)微流體系統作為驅動元件，光子晶體作為感測元件進行二倍稀釋的免標定分析。藉由光學特性的量測、蔗糖溶液的驅動實驗及免標定生物實驗驗證晶片的性能，成功在晶片上完成待測液體的兩倍稀釋與感測步驟之LOC檢測平台。本論文成功的將濃度為60 %之蔗糖溶液稀釋為濃度10 %之蔗糖溶液，成功做出共振波長與蔗糖濃度關係之校正曲線，靈敏度為44 nm/RIU。

Traditional immunoassay experiment including antibody immobilized, sample dilution, reagent mixing, marking, regenerate, washing etc, is tedious and highly repetitive and needs different equipment to operate each step. The concept of Lab-on-a-chip (LOC) attempts to integrate all experimental steps into one chip. . Using digital microfluidic system as an operating platform has many advantages: easy manufacture, work without pumps or valves, no blocking issue, less waste of samples, and programmable computer controlled automatic progress. These advantages are consistent with the needs of biomedical research. In clinical diagnosis, immunoassay based on fluorescence detection is the most common technique for disease detection; however, it requires to conjugate fluorophores with biomolecules. Hence, it is a time-consuming process and fluorescence quenching could be a potential issue. This study develops a LOC system which combines electrowetting-on-dielectric (EWOD)chip and photonic crystal (PC) chip for label-free detection. Through reflection measurement, we accomplish two-fold serial dilution and successfully measured different concentrations of sucrose solutions. The sensitivity of our device is 44 nm/RIU.