Enhanced Thermometric Sensor for Arsenate Analysis Based on Dual Temperature Readout Signaling Strategy

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Urgent need for portable and sensitive arsenate detection methods.
• Limitations of current complex analytical techniques for field use.
• Development of simple, instrument-free detection strategies is crucial.

Purpose of the Study:

• To develop a simple, sensitive, and portable thermometric strategy for arsenate determination.
• To utilize cobalt oxyhydroxide (CoOOH) nanoflakes for arsenate sensing.
• To achieve effective signaling amplification using dual temperature responses.

Main Methods:

• Employing cobalt oxyhydroxide (CoOOH) nanoflakes to catalyze hydrogen peroxide decomposition.
• Utilizing exothermic and endothermic reactions for temperature signaling.
• Measuring dual temperature responses (increasing and decreasing) for arsenate quantification.
• Coupling "signal-on" and "signal-off" temperature readouts for enhanced sensitivity.

Main Results:

• The CoOOH nanoflake-based thermometric strategy demonstrated sensitivity to arsenate.
• Arsenate presence inhibited CoOOH catalytic activity, altering temperature responses.
• A good linear relationship was observed between temperature readout and arsenate concentration.
• A low detection limit of 51 nM (3.8 ppb) was achieved for arsenate.
• The method showed comparable performance to ICP-MS but with enhanced portability and simplicity.

Conclusions:

• The developed thermometric strategy provides a simple, rapid, convenient, and low-cost platform for arsenate detection.
• This method is suitable for portable sensing of arsenate in real environmental water samples.
• The dual superimposing temperature readout offers effective signaling amplification.
• The strategy overcomes the need for complex instruments and skilled technicians in arsenate analysis.