A Pencil-Drawn Electronic Tongue for Environmental Applications

Area of Science:

• Electroanalytical Chemistry
• Environmental Science
• Materials Science

Background:

• Accurate water quality monitoring is crucial for environmental protection and public health.
• Existing analytical methods can be expensive, time-consuming, or require specialized equipment.
• Development of cost-effective and portable sensing technologies is needed for field applications.

Purpose of the Study:

• To develop a simple, cost-effective potentiometric sensor array for analyzing inorganic ions in aqueous media.
• To evaluate the performance of the sensor array as an "electronic tongue" for real-life water samples.
• To quantify key water quality parameters using the developed sensor system.

Main Methods:

• Fabrication of a potentiometric sensor array using graphite and zeolite composite pencils on a polymeric support.
• Testing the sensor array's sensitivity to various inorganic ions in aqueous solutions.
• Application of the sensor array to analyze 100 real-surface water samples from Indian rivers.
• Utilizing partial least squares (PLS) regression for data analysis and water quality parameter quantification.

Main Results:

• The sensor array exhibited distinct sensitivity to a range of inorganic ions.
• Successful quantitative analysis of real-life surface water samples was achieved.
• The electronic tongue accurately quantified total hardness, total alkalinity, and calcium content with mean relative errors below 18%.

Conclusions:

• The developed potentiometric sensor array offers a simple and cost-effective solution for water quality monitoring.
• The 'drawing' technique provides a facile method for sensor fabrication.
• The electronic tongue system demonstrates significant potential for field-deployable analysis of environmental water samples.