A New Eosin Y and Hydroxybenzaldehyde Coupled Probe for Instantaneous Sensing of Cu2+ by Colorimetric and ‘Turn‐off’ Fluorescence Methods
Year: 2025
Type: article
Abstract: Xanthene‐based organic chemosensors for detecting metal ions are a topic of research. While Rhodamine and Fluorescein‐based sensors are more common, fewer research articles exist on Eosin‐based sensors. Herein, a new chemosensor (EY‐S) is reported that was obtained efficiently in two high‐yielding reaction steps from commercially procured Eosin Y. EY‐S is a fluorescent molecule that can selectively detect cupric (Cu2+) ions in the presence of other competing metal ions. The colorimetric sensing of Cu2+ ions was studied using uv‐vis spectroscopy. The green fluorescence of EY‐S was effectively quenched by Cu2+ and quantified by fluorescence titration. A high magnitude of the Stern‐Volmer (Ksv) constant advocated efficient quenching. Job's plot confirmed a 1 : 1 complexation ratio between EY−S and Cu2+. The association constant (Ka) for the host‐guest complexation was determined to be 1.59×105 M−1. The limit of detection (LOD) associated with the detection of Cu2+ was 3.29 nM, indicating the high sensitivity of the EY−S sensor. Cu2+ detection was also tested using actual water samples collected from various sources, and EY−S′ performance remained uncompromised. The sensor could detect Cu2+ in acidic, neutral, and essential media, with the sensing being most efficient at higher pH. The EY‐S sensor/probe could be easily recycled multiple times without significantly declining Cu2+ detection performance. A mechanism of binding between EY‐S and Cu2+ was also proposed.
Authors: Arnab Chakraborty, Neeladri Das
Institution: Indian Institute of Technology Patna
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4407593011