# Quantum noise limited nanoparticle detection with exposed-core fiber

## TL;DR

This paper introduces a robust, quantum noise limited exposed-core fiber sensor capable of detecting single nanoparticles as small as 25 nm, offering a sensitive and biocompatible platform for label-free biosensing.

## Contribution

The development of a novel exposed-core fiber sensor that achieves quantum noise limited detection and can be integrated with microfluidics for label-free biosensing.

## Key findings

- Detected single nanoparticles down to 25 nm radius
- Operates at optical intensities below biophysical damage thresholds
- Provides a robust platform suitable for microfluidic integration

## Abstract

Label-free biosensors are important tools for clinical diagnostics and for studying biology at the single molecule level. The development of optical label-free sensors has allowed extreme sensitivity, but can expose the biological sample to photodamage. Moreover, the fragility and complexity of these sensors can be prohibitive to applications. To overcome these problems, we develop a quantum noise limited exposed-core fiber sensor providing robust platform for label-free biosensing with a natural path toward microfluidic integration. We demonstrate the detection of single nanoparticles down to 25 nm in radius with optical intensities beneath known biophysical damage thresholds.