Refractive index and sensing of glucose molarities determined using Au-Cr K-SPR at 670/785 nm wavelength

• Main Authors: P. Susthitha Menon (Author), Mulyanti, Budi (Author), Nur Akmar Jamil (Author), Wulandari, Chandra (Author), Nugroho, Harbi Setyo (Author), Gan, Siew Mei (Author), Noor Faizah Zainul Abidin (Author), Hasanah, Lilik (Author), Pawinanto, Roer Eka (Author), Dilla Duryha Berhanuddin (Author)
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia, 2019-06.
• Online Access: Get fulltext

 In this paper, we determine the optical refractive indices of different molarities of glucose using nano-laminated gold/chromium (Au-Cr) thin film via Kretschmann-based Surface Plasmon Resonance (K-SPR) sensing with angular interrogation. The nano-laminated Au-Cr K-SPR sensor detects the glucose presence in low- and high-concentration of 4-12 mmol/L and 55-277 mmol/L, respectively, under the exposure of 670 nm and 785 nm optical wavelengths. The experimental results showed that the minimum limit of detection (LOD) of Au-Cr K-SPR is 4 mmol/L and the glucose sensor sensitivities are in average of 3.41 o/M and 2.73o/M at 670 nm and 785 nm optical wavelength, respectively. Stable sensitivity for each concentration also shown from the sensorgram results, indicates the stable performance of nano-laminated Au-Cr SPR sensor to detect glucose in the range from mmol/L up to dmol/L. Values of refractive indices for glucose molarities obtained are 1.33187 (4 mmol/L) and 1.3191 (4 mmol/L) at 670 and 785 nm wavelength, respectively. These RI values are beneficial for numerical simulation of glucose sensors using nano-laminated Au-Cr thin films which have been reported for the first time. The sensor can be eventually deployed in integrated photonic sensing devices comprising of multiple analyte detection for lab-on-chip (LoC) and point-of care (PoC) applications.