Department of Life Science , University of Seoul , Seoul 130-743 , Republic of Korea.
Department of Chemical and Biomolecular Engineering , Sogang University , Seoul 121-742 , Republic of Korea.
ACS Appl Mater Interfaces. 2018 Apr 18;10(15):13226-13235. doi: 10.1021/acsami.8b01550. Epub 2018 Apr 3.
Owing to its high sensitivity and high selectivity along with rapid response time, plasmonic detection has gained considerable interest in a wide variety of sensing applications. To improve the fieldwork applicability and reliability of plasmonic detection, the integration of plasmonic nanoparticles into optical devices is desirable. Herein, we propose an integrated label-free detection platform comprising a plasmonic cavity that allows sensitive molecular detection via either surface-enhanced Raman scattering (SERS) or plasmon resonance energy transfer (PRET). A small droplet of metal ion solution spontaneously produces a plasmonic cavity on the surface of uncured poly(dimethylsiloxane) (PDMS), and as PDMS is cured, the metal ions are reduced to form a plasmonic antennae array on the cavity surface. Unique spherical feature and the integrated metallic nanoparticles of the cavity provide excellent optical functions to focus the incident light in the cavity and to rescatter the light absorbed by the nanoparticles. The optical properties of the plasmonic cavity for SERS or PRET are optimized by controlling the composition, size, and density of the metal nanoparticles. By using the cavity, we accomplish both 1000-fold sensitive detection and real-time monitoring of reactive oxygen species secreted by live cells via PRET. In addition, we achieve sensitive detection of trace amounts of toxic environmental molecules such as 5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazol-3-one (CMIT/MIT) and bisphenol A, as well as several small biomolecules such as glucose, adenine, and tryptophan, via SERS.
由于具有高灵敏度、高选择性和快速响应时间，等离子体检测在各种传感应用中引起了相当大的兴趣。为了提高等离子体检测的现场适用性和可靠性，将等离子体纳米粒子集成到光学器件中是可取的。在此，我们提出了一种集成的无标记检测平台，包括一个等离子体腔，通过表面增强拉曼散射（SERS）或等离子体共振能量转移（PRET）可以实现灵敏的分子检测。一小滴金属离子溶液在未固化的聚二甲基硅氧烷（PDMS）表面自发产生等离子体腔，随着 PDMS 的固化，金属离子被还原形成等离子体天线阵列在腔表面。独特的球形特征和集成的金属纳米粒子腔提供了出色的光学功能，可将入射光聚焦在腔体内并重新散射被纳米粒子吸收的光。通过控制金属纳米粒子的组成、尺寸和密度，可以优化等离子体腔的 SERS 或 PRET 光学性能。通过使用该腔，我们通过 PRET 实现了活细胞分泌的活性氧的 1000 倍灵敏检测和实时监测。此外，我们还通过 SERS 实现了对痕量有毒环境分子如 5-氯-2-甲基-4-异噻唑啉-3-酮/2-甲基-4-异噻唑啉-3-酮（CMIT/MIT）和双酚 A 以及葡萄糖、腺嘌呤和色氨酸等几种小生物分子的敏感检测。
