# Fluorophore-Probed Curdlan Polysaccharide Chemosensor: “Turn-On” Oligosaccharide Sensing in Aqueous Media

## TL;DR

A new chemosensor detects acarbose in water using a fluorescence 'turn-on' method, which could help in disease-related sugar detection.

## Contribution

A rhodamine-modified Curdlan chemosensor with a 'turn-on' fluorescence response for acarbose detection in aqueous media.

## Key findings

- Rhod-Cur detects acarbose with a 5 μM limit of detection.
- Fluorescence 'turn-on' is due to globule-to-coaggregation conversion upon acarbose insertion.
- The sensor shows high sensitivity and selectivity for acarbose among tested saccharides.

## Abstract

The ability to sense
saccharides in aqueous media has attracted
much attention in multidisciplinary sciences because the detection
of ultrahigh concentrations of sugar chains associated with serious
diseases could lead to further health promotion. However, there are
notable challenges. In this study, a rhodamine-modified Curdlan (Rhod-Cur) chemosensor was synthesized that exhibited distinctive
fluorescence “turn-on” responses. Rhod-Cur exhibited simultaneous sensitive and selective sensing of clinically
useful acarbose with a good limit of detection (5 μM) from among
those of the saccharides examined. The (chir)optical properties of Rhod-Cur were elucidated using UV/vis, fluorescence, excitation,
and circular dichroism spectroscopies; lifetime measurements and morphological
studies using atomic force and confocal laser scanning microscopy
and dynamic light scattering techniques revealed that the fluorescence
“turn-on” behavior originates from globule-to-coaggregation
conversion upon insertion of the oligosaccharides in the dynamic Cur
backbone.