# Highly Sensitive Temperature Sensing in Biological Region with Ratiometric Fluorescent Response

## TL;DR

This paper introduces a new thermometer using biocompatible polymers that can measure temperature changes in living cells with high sensitivity and accuracy.

## Contribution

The novel contribution is the development of a ratiometric fluorescent thermometer using POx, TPE, and HBO for precise biological temperature sensing.

## Key findings

- The thermometer achieves ultrahigh sensitivity and good reversibility in biological temperature measurements.
- It enables accurate temperature monitoring in living cells with a large fluorescence difference.
- The device uses a phase transition mechanism for ratiometric fluorescence response.

## Abstract

Poly(2-oxazoline) (POx), a typical thermoresponsive polymer with good biocompatibility, was conjugated with environment-sensitive tetraphenylenethene (TPE) and hydroxyphenylbenzoxazole (HBO) to achieve unique thermometer readings. Through phase transition induced by temperature, the thermometers can measure temperature in biologic range with ratiometric fluorescence response, ultrahigh sensitivity and good reversibility. Moreover, the thermometer can be used to measure the change in temperature with large fluorescence difference in living cells.