School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China.
School of Information Engineering, Guangdong Provincial Key Laboratory of Photonics Information Technology, Guangdong University of Technology, Guangzhou 510006, China.
ACS Biomater Sci Eng. 2022 Mar 14;8(3):1060-1066. doi: 10.1021/acsbiomaterials.1c01565. Epub 2022 Feb 25.
Highly sensitive detection of refractive index (RI) is essential for the analysis of the bio-microenvironment and basic cellular reactions. To achieve this, optic-fiber RI sensors based on localized surface plasmon resonance (LSPR) have been widely used for their flexibility and high sensitivity. However, the current optic-fiber RI sensors are mainly fabricated using glass, which makes them face the challenges in biocompatibility and biosafety. In this work, a RI sensor with high sensitivity is fabricated using metal-nanostructure-decorated spider silk. The spider silk, which is directly dragged from , is natural protein-based biopolymer with low attenuation, good biocompatibility and biodegradability, large RI, great flexibility, and easy functionalization. Hence, the spider silk can be an ideal alternative to glass for sensing in biological environments with a wide RI range. Different kinds of metal nanostructures, such as gold nanorods (GNRs), gold nanobipyramids (GNBP), and Ag@GNRs, are decorated on the surface of the spider silk utilizing the surface viscidity of the silk. By directing a beam of white light into the spider silk, the LSPR of the metal nanostructures was excited and a highly sensitive RI sensing (the highest sensitivity of 1746 nm per refractive index was achieved on the GNBP-decorated spider silk) was obtained. This work may pave a new way to precise and sensitive biosensing and bioanalysis.
高灵敏度的折射率（RI）检测对于生物微环境分析和基本细胞反应至关重要。为了实现这一目标，基于局域表面等离子体共振（LSPR）的光纤 RI 传感器因其灵活性和高灵敏度而得到了广泛应用。然而，目前的光纤 RI 传感器主要是使用玻璃制造的，这使得它们在生物相容性和生物安全性方面面临挑战。在这项工作中，使用金属纳米结构修饰的蜘蛛丝制造了一种高灵敏度的 RI 传感器。蜘蛛丝是一种直接从蜘蛛身上提取的天然蛋白质基生物聚合物，具有低衰减、良好的生物相容性和生物降解性、大的 RI、极好的柔韧性和易于功能化等特点。因此，蜘蛛丝可以作为玻璃的理想替代品，用于在具有宽 RI 范围的生物环境中进行传感。不同种类的金属纳米结构，如金纳米棒（GNRs）、金纳米双锥体（GNBP）和 Ag@GNRs，利用丝的表面粘性被修饰在蜘蛛丝的表面上。通过将一束白光导入蜘蛛丝，金属纳米结构的 LSPR 被激发，从而实现了高灵敏度的 RI 传感（在 GNBP 修饰的蜘蛛丝上实现了最高 1746nm/RI 的灵敏度）。这项工作可能为精确和敏感的生物传感和生物分析开辟了一条新途径。
