An on-chip dense waveguide-based nanoparticle sensor and its sensing method

Abstract

The invention discloses an on-chip intensive waveguide-based nanoparticle sensor and a sensing method thereof. A single waveguide is horizontally wound around a surface of a substrate to form an intensive waveguide with maximum density under a condition that coupling is not generated, detection light is scattered or absorbed by nanoparticles when the nanoparticles attached onto a surface of the intensive waveguide are arranged within an evanescent field of a waveguide mode, an abruptly-descending step signal is generated by transmitting power, the size information of the nanoparticle is codedby the step signal, whether the nanoparticle exists or not is judged through identifying the step signal by a computer, and the size information of the nanoparticle is obtained. The intensive waveguide is large in sensing area, and the sensing area is expanded than that of a straight waveguide by two orders of magnitude; meanwhile, the capturing efficiency is high, and the time response is rapid,and the nanoparticle small sphere with radius being 100 nanometers can be detected; and moreover, the scattering signal of the waveguide mode of TM polarization is 30 times of that of TE polarization.

Description

technical field [0001] The invention relates to nanoparticle sensing technology, in particular to a nanoparticle sensor based on an on-chip dense waveguide and a sensing method thereof. Background technique [0002] At present, related fields such as homeland security, environmental monitoring, and early diagnosis are in urgent need of in-situ, rapid, ultra-sensitive, and reproducible detection platforms for nanoscale particles. Among various sensors, optical evanescent field sensors have attracted more and more attention due to many unique advantages, such as high sensitivity, no labeling, and non-invasiveness. In recent years, related studies have mainly focused on exploring new mechanisms to enhance the sensitivity of sensors. For example, the use of singular points in the microcavity or the combination of plasmon enhancement effect can improve the sensitivity of the sensor to the detection of single biomolecules and single atoms. Nanofibers exploit the concept of photo...

AI Technical Summary

Problems solved by technology

Although the sensitivity of these sensors has exceeded the requirements of current applications, the following aspects seriously hinder the promotion of their practical applications: 1. The sensing area of ​​the micro-nano scale resonant cavity is extremely small, so it takes a very long time to capture and characterize nanoparticles

Although nanofiber coils and arrays can increase the detection area, the low axial uniformity of nanofibers, difficulty in integrating with microfluidics, and associated nanofiber fixtures limit the practical application of such sensors.

2. High power densities in microcavities and plasmonic resonators can have photodestructive effects on biomolecules

3. The preparation process of optical sensors such as nanofibers, microcavities and semi-continuous plasmonic films is difficult to achieve precise control, resulting in inconsistent performance of the prepared sensors

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