Chen Pengwei, Huang Yunyun, Bo Ye, Liang He, Xiao Aoxiang, Guan Bai-Ou
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 511143, China.
Chem Eng J. 2021 Mar 1;407:127143. doi: 10.1016/j.cej.2020.127143. Epub 2020 Sep 29.
Portable devices, which can detect and characterize the individual nanoparticles in real time, are of insignificant interest for early diagnosis, homeland security, semiconductor manufacturing and environmental monitoring. Optical microfibers present a good potential in this field, however, are restricted by the sensitivity limit. This study reports the development of a 3D plasmonic nanointerface, which is made of a Cu-BTC framework supporting CuP nanocrystals, enhancing the optical microfiber for real-time detection and sizing of single nanoparticles. The CuP nanocrystals are successfully embedded in the 3D Cu-BTC framework. The localized-surface plasmon resonance is tuned to coincide with the evanescent field of the optical microfiber. The 3D Cu-BTC framework, as the scaffold of nanocrystals, confines the local resonance field on the microfiber with three dimensions, at which the binding of target nanoparticles occurs. Based on the evanescent field confinement and surface enhancement by the nanointerface, the optical microfiber sensor overcomes its sensitivity limit, and enables the detection and sizing of the individual nanoparticles. The compact size and low optical power supply of the sensor confirm its suitability as a portable device for the real-time single-nanoparticle characterization, especially for the convenient evaluation of the ultrafine particles in the environment. This work opens up an approach to overcome the sensitivity limit of the optical microfibers, as long with stimulating the portable real-time single-nanoparticle detection and sizing.
能够实时检测和表征单个纳米颗粒的便携式设备，在早期诊断、国土安全、半导体制造和环境监测方面的应用价值不大。光学微纤维在该领域具有良好的潜力，然而，其受到灵敏度极限的限制。本研究报道了一种三维等离子体纳米界面的开发，该界面由支撑CuP纳米晶体的Cu-BTC框架制成，用于增强光学微纤维以实现对单个纳米颗粒的实时检测和尺寸测量。CuP纳米晶体成功嵌入三维Cu-BTC框架中。局域表面等离子体共振被调整为与光学微纤维的倏逝场相匹配。三维Cu-BTC框架作为纳米晶体的支架，在三个维度上限制了微纤维上的局部共振场，目标纳米颗粒在此处发生结合。基于纳米界面的倏逝场限制和表面增强作用，光学微纤维传感器克服了其灵敏度极限，能够对单个纳米颗粒进行检测和尺寸测量。该传感器紧凑的尺寸和低光功率需求证实了其作为便携式设备用于实时单纳米颗粒表征的适用性，特别是用于方便地评估环境中的超细颗粒。这项工作开辟了一种克服光学微纤维灵敏度极限的方法，同时推动了便携式实时单纳米颗粒检测和尺寸测量技术的发展。
