本研究中，我們以金(Au)奈米顆粒及氮化銦鎵(InGaN)奈米量子井，製成表面增強拉曼散射(Surface Enhanced Raman Scattering, SERS)感測晶片。InGaN奈米量子井是以有機金屬氣相沉積系統磊晶而成的。我們以此氮化物SERS晶片測量不同濃度的葡萄糖(glucose)光譜，希望得到高強度、高穩定的拉曼訊號。為了提高感測靈敏度，我們的製程優化聚焦在金屬厚度的調整。本研究採用的Au奈米顆粒，來自於高溫退火的Au薄膜，由於SERS訊號強度取決於Au奈米顆粒形成的局部表面電漿共振(localized surface plasmon resonance, LSPR)效應，對奈米顆粒的尺寸、密度非常敏感，而Au薄膜的厚度，又是影響奈米顆粒尺寸、密度的關鍵條件，改變Au薄膜厚度會讓葡萄糖的SERS訊號產生明顯的強度變化。經過一系列的測試，我們發現以10 nm 的Au薄膜，搭配700 °C、2小時的退火條件，可以得到最強的葡萄糖濃度，並可感測到2 g/L的最低濃度極限。

In this study, we fabricated surface-enhanced Raman scattering (SERS) substrates, using Au nanoparticles and InGaN nanostructured quantum wells. The nitride structure was grown by metal-organic chemical vapor deposition (MOCVD). We used the SERS substrate to detect glucose at varied concentrations, aiming to obtain strong and stable Raman signals. In order to enhance the sensitivity, the fabrication optimization focused on the control of Au-film thickness. The Au nanoparticles were attained by annealing an Au thin film. Since SERS signals of glucose come from the localized surface plasmon resonance (LSPR) effect induced by Au nanoparticles, Au-film thickness and the annealing condition should be prudently selected to form the nanoparticles with proper dimension/density, so that the LSPR effect can be maximized. After a systematic characterization, it is found the SERS substrate attained with a 10-nm thick Au film and the annealing at 700 °C for 2 hours can deliver the highest SERS signal of glucose. With this condition, the glucose can be detected at the concentration down to 2 g/L.

[1] wikipedia：Raman spectroscopy
(Https://en.wikipedia.org/wiki/Raman_spectroscopy)
[2] Raju Botta, A., Rajanikanth, C., Bansal. Silver nanocluster films for glucose sensing by Surface Enhanced Raman Scattering (SERS). Sens. Bio-Sens. Res. 9, 13-16 (2016).
[3] Leonardo Perez-Mayen, Jorge Oliva, P. Salas, Elder De la Rosa. Nanomolar detection of glucose using SERS substrates fabricated with albumin coated gold nanoparticles. Nanoscale 8, 11862-11869 (2016).
[4] Xiaoqi Fu, Tingshun Jiang, Qian Zhao, Hengbo Yin. Charge-transfer contributions in surface-enhanced Raman scattering from Ag, Ag2S and Ag2Se substrates. J. Raman Spectrosc. 43, 1191–1195 (2012).
[5] 科技大觀園：表面電漿現象及其應用
(https://scitechvista.nat.gov.tw/Article/C000003/detail?ID=f782b1bc-dc51-4538-abaf-1eae14d928e6)
[6] M. Bańkowska, J. Krajczewski, I. Dzięcielewski, A. Kudelski, and J. L. Weyher. Au−Cu Alloyed Plasmonic Layer on Nanostructured GaN for SERS Application. J. Phys. Chem. C 120, 1841-1846 (2016).
[7] Bence Kozmaa, Edit Hirschc, Szilveszter Gergelyb, László Pártaa, Hajnalka Patakic,András Salgób. On-line prediction of the glucose concentration of CHO cellcultivations by NIR and Raman spectroscopy: Comparative scalabilitytest with a shake flask model system. J. Pharm. Biomed. Anal. 145, 346–355 (2017).
[8] K.P. Sooraj, Mukesh Ranjan, Rekha Rao, Subroto Mukherjee. SERS based detection of glucose with lower concentration than blood glucose level using plasmonic nanoparticle arrays. Appl. Surf. Sci. 447, 576-581 (2018).
[9] 維基百科：有機金屬化學氣相沉積法
(https://zh.wikipedia.org/wiki/%E6%9C%89%E6%9C%BA%E9%87%91%E5%B1%9E%E5%8C%96%E5%AD%A6%E6%B0%94%E7%9B%B8%E6%B2%89%E7%A7%AF%E6%B3%95)
[10] Jui-Wei Hus, Chien-Chia Chen, Ming-Jui Lee, Hsueh-Hsing Liu, Jen-Inn Chyi, Michael R. S. Huang, Chuan-Pu Liu, Tzu-Chiao Wei, Jr-Hau He, and Kun-Yu Lai. Bottom-Up Nano-heteroepitaxy of Wafer-Scale Semipolar GaN on (001) Si. Adv. Mater. 27, 4845–4850 (2015).
[11] Hongxing Xu, Erik J. Bjerneld, Javier Aizpurua, Peter Apell, Linda Gunnarsson, Sarunas Petronis, Bengt Kasemo, Charlotte Larsson, Fredrik Höök, and Mikael Käll. Interparticle coupling effects in surface-enhanced Raman scattering. Nanoparticles and Nanostructured Surfaces: Novel Reporters with Biological Applications 4258, 35-42 (2001).