| 초록 |
We have developed a surface-enhanced Raman scattering (SERS) contact lens for selective glucose detection in human tears. The proposed SERS contact lens composed of silver nanowires (AgNWs), 4-mercaptophenyl boronic acid (MPBA), and silk fibroin was fabricated to form a flexible patch-type substrate. The silk fibroin layer offered an excellent biocompatible interface and it was functioned as a filter layer for proteins exclusion in tears. AgNWs on silk fibroin formed a high density of hot spots for Raman signal enhancement and the chemical receptor (MPBA) coated on AgNWs (MPBA-AgNWs) induced cis-diol complexation with glucose molecule, enabling selective sensing of tear glucose level. After materials characterization of the integrated SERS contact lens using SEM, FT-IR, XPS and so on, glucose sensing performance was studied. The developed SERS contact lens exhibited excellent sensing performance in the glucose detection range of 500 nM - 1 mM, with the detection limit of 245 nM. Then, the sensing capability was demonstrated using human tears before and after a meal, which was also compared with the commercially available glucometer. As a result, the tear glucose concentration trend was similar to that of plasma glucose level, confirming the feasibility of the developed SERS contact lens for non-invasive human glucose monitoring. The developed SERS contact lens is expected to be utilized as various wearable biosensors such as metabolite and chemical bio-marker monitoring in bio-fluids. |
