應用石墨烯於光電平行讀取葡萄糖感測元件

Abstract

光電平行讀取異質接面葡萄糖感測元件，使用高品質石墨烯製成，其靈敏度可量測範圍從1 nM 至 100 mM，未來有極大的機會發展成光電平行非侵入式葡萄糖感測元件，解決糖尿病病患偵測上的不便，也可以透過平行傳輸系統，加速訊號傳遞，可增加封閉迴圈胰島素幫浦胰島素幫浦的實際應用價值。在此篇論文中，我們製成石墨烯/氧化鋅/二氧化矽/ P型氮化鎵的穿遂型發光二極體，其特殊的工作原理，透過葡萄糖和葡萄糖氧化酵素酶，產生氧氣，參雜石墨烯表面，改變石墨烯的費米能接後，測得電流載子在不同的蕭特基未位障下的變化，間接得知葡萄糖濃度。另外，透過二氧化矽絕緣層，累積電子於二氧化矽/ P型氮化鎵介面，增加電子電洞復合機率，導致在界面層發光，因此可以透過光學量測以及電學量測，測得葡萄糖濃度，這些優異的性質，有極大的機會發展成，可攜帶式、非侵入式、以及平行光電傳輸的葡萄糖感測元件。

Optically and electrically readable glucose sensors based on high quality graphene vertically stacked heterojunctions with ultrahigh sensitivity has been designed, fabricated and demonstrated. Its sensing mechanism makes use of the large variation in the Fermi energy of graphene upon electrons doping from oxygen molecules generated by electrochemical process of glucose oxidase at the presence of glucose molecule. A semiconductor sieve layer with suitable band alignment to prevent charge transfer from graphene can greatly enhance the sensitivity. And an insulating layer to create electron-hole pairs accumulation near the interface is very useful for light emission. Combining all these unique features together, it results in superior detection both in optical and electric performance. Through measurements of current-voltage characteristics and electroluminescence spectra, this novel structure responds to glucose concentrations covering a wide range from as low as 1 nM to 100 mM. All these superior properties show a great potential for the development of portable, noninvasive, and parallel readable glucose sensors.