A photonic crystal cavity-optical fiber tip nanoparticle sensor for biomedical applications

TL;DR

This paper introduces a novel optical fiber sensor with a photonic crystal cavity that detects nanoparticles in solutions by inducing aggregation and measuring changes in photoluminescence, promising biomedical applications.

Contribution

It presents a new fiber-optic nanoparticle sensor that combines convective and optical trapping to detect and quantify nanoparticles directly on the cavity surface.

Findings

Detects gold and iron oxide nanoparticles effectively.

Uses photoluminescence changes to determine nanoparticle presence.

Operates in solution-based biomedical environments.

Abstract

We present a sensor capable of detecting solution-based nanoparticles using an optical fiber tip functionalized with a photonic crystal cavity. When sensor tips are retracted from a nanoparticle solution after being submerged, we find that a combination of convective fluid forces and optically-induced trapping cause an aggregation of nanoparticles to form directly on cavity surfaces. A simple readout of quantum dot photoluminescence coupled to the optical fiber shows that nanoparticle presence and concentration can be detected through modified cavity properties. Our sensor can detect both gold and iron oxide nanoparticles and can be utilized for molecular sensing applications in biomedicine.