Sizing and identification of nanoparticles by a tapered fiber.

Huiling Pan,Hongxiang Lei,Weina Zhang

doi:10.1039/c8ra06454g

Abstract

There is a strong desire for sizing and identification of nanoparticles in fields of advanced nanotechnology and environmental protection. Although existing approaches can size the nanoparticles, or identify nanoparticles with different refractive indexes, a fast and simple method that combines the two functions still remains challenges. Here, we propose a versatile optical method to size and identify nanoparticles using an optical tapered fiber. By detecting reflection signals in real time, 400–600 nm SiO2 nanoparticles can be sized and 500 nm SiO2, PMMA, PS nanoparticles can be identified. This method requires only an optical tapered fiber, avoiding the use of elaborate nanostructures and making the device highly autonomous, flexible and compact. The demonstrated method provides a potentially powerful tool for biosensing, such as identification of nano-contaminant particles and biological pathogens.

Highlights

The sizing and identi cation of nanoparticles are becoming increasingly important for applications in various elds, such as environmental protection, disease diagnosis and treatment, as well as scienti c research applications.[1,2,3] For example, many of the body's physical diseases, including allergies and lung cancer, are caused by the inhalation of tiny particles, as well as particulates emitted from automobiles and industries, which cause environmental pollution.[4,5,6] more attention should be paid to nanoparticles, including sizing and identi cation
There is a strong desire for sizing and identification of nanoparticles in fields of advanced nanotechnology and environmental protection
The results show that the SiO2 nanoparticle and polymethyl methacrylate (PMMA) nanoparticle were trapped by the TF with an optical power of 12 mW, but the PS nanoparticle was pushed away

Summary

Introduction

The sizing and identi cation of nanoparticles are becoming increasingly important for applications in various elds, such as environmental protection, disease diagnosis and treatment, as well as scienti c research applications.[1,2,3] For example, many of the body's physical diseases, including allergies and lung cancer, are caused by the inhalation of tiny particles, as well as particulates emitted from automobiles and industries, which cause environmental pollution.[4,5,6] more attention should be paid to nanoparticles, including sizing and identi cation. There are many ways to size nanoparticles today, such as by using a scanning mobility particle sizer,[7] laser particle analyzer[8] and Scanning Electron Microscopy.[9] Compared to the traditional methods, recently developed optical sizing techniques show great superiority in time response, low cost, and non-invasiveness in sizing particles.[10,11] Especially for the techniques of microcavity sensing,[12,13,14] interferometric scattering and photothermal microscopy,[15,16,17] the detection limit is down to single nanoparticles. The microcavity sensing pursuits high Q factors up to 108 and small mode volumes to enable signi cant enhancement of light–matter interactions; it can detect the nanoparticles as low as 30 nm, but it needs elaborate cavity system and a tunable laser source; the interferometric scattering can detect

Methods

Results

Conclusion