於步調快速的當今，人們往往追求效率而忽略了自身的健康，導致糖尿病患者的數量節節上升，因此糖尿病的偵測和預防遂成為一項不可避免的議題，根據研究指出，糖化血色素能有效偵測或防治糖尿病併發症的產生，與一般血糖不同的是，糖化血色素短時間內不易受到運動、飲食的影響有大幅的變化，所以用糖化血色素作為糖尿病的偵測依據較為精準可靠。當今量測糖化血色素的技術仍受到成本昂貴，操作複雜，不易攜帶等限制，因此本篇的研究便著重在研發出一種成本較低，可攜式的生物感測晶片。
本篇研究採用了環形指叉電極來偵測糖化血色素所佔的比例，重點不單純著重在量測出糖化血色素的濃度，更是要量出糖化血色素所占整體血色素的比例，正常人的糖化血色素所占比例約在5%左右，一般來講，如果大於7%就可視為糖尿病患者，首先為了在電極上面固定住蛋白質，得先將自主性單分子層附著於金電極上面，蛋白質與單分子層間的交互作用會使得蛋白質鍵結上去，蛋白質附著的多寡會影響到交流電阻抗的變化，以其不同的阻抗變化情形便可推測出蛋白質的濃度，而為了得到糖化血色素所占的比例，本篇利用將包含所有血色素的濃度和僅有糖化血色素的濃度做比較，此種情況需要兩個電極陣列來做阻抗量測，以及在量測的玻片前端加入了分離糖化血色素的流道，最後藉由附著前和附著後的阻抗變化，成功檢測出了7%的糖化血色素，本研究已相當接近實際病理學上的應用。

It’s essential to monitor the long-term glucose concentration in the blood of the diabetic patients, and glycated hemoglobin (HbA1c) has became one of the most important mark to diagnose. This study presents an on-chip biosensor for detecting the glycated hemoglobin as a ratio to total hemoglobin (Hb) based on impedance measurement. In the measurement process, no any other reagent is required. It’s label-free, and low sample volume needed.
The ring-shaped interdigital electrodes were coated with the self-assembled monolayer (SAM) to immobilize the proteins and measured the before-after impedance deviations via the impedance analyzer. The roughness of glass substrates was further improved by buffer oxide etchant (BOE), and distribution uniformity of the proteins were also improved which was examined by fluorescent images.
Various concentrations of Hb and HbA1c were measured via before-after impedance deviations. After HbA1c separation process, the ratio of HbA1c to total Hb was measured by the differential capacitance ΔC of the proteins calculated from the equivalent circuit model. ΔC would rise with the percentage of HbA1c, and was good linearity after 7% in 200 ng/µL Hb and HbA1c. The proposed detection method is much close to actual point-of-care diagnostics to diabetic patients with the advantage of low-cost and easy fabrication.

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