Paper-based plasticizer-free sodium ion-selective sensor with camera phone as a detector

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Ion-selective optodes are crucial for chemical sensing.
• Traditional optodes often require complex fabrication and organic polymers.

Purpose of the Study:

• To introduce a novel ionophore-based ion-selective optode platform utilizing cellulose paper.
• To demonstrate the feasibility of paper as a substrate for heterogeneous optical ion sensing.

Main Methods:

• Cellulose paper was used as a substrate for adsorbing chromoionophore, ionophore, and ion-exchanger species.
• The adsorbed components formed a hydrophobic phase for sensing.
• A sodium optode was used as a model system.

Main Results:

• Cellulose paper proved to be an excellent substrate for the necessary sensing components.
• A hydrophobic phase was successfully formed on the paper substrate.
• Heterogeneous optical ion sensing was achieved without the need for plasticizers or organic polymers.

Conclusions:

• Paper-based ion-selective optodes offer a promising, simplified approach to optical ion sensing.
• This platform demonstrates the potential for low-cost, disposable sensing devices.