Printed disposable colorimetric array for metal ion discrimination

Area of Science:

• Analytical Chemistry
• Materials Science
• Sensor Technology

Background:

• Reproducibility issues in optical sensing array preparation (spin coating, drop casting) limit discriminatory power.
• Non-homogeneous membranes produced by traditional methods hinder accurate colorimetric analysis.

Purpose of the Study:

• To enhance the discriminatory power of colorimetric sensor arrays.
• To improve the reproducibility of sensing membrane preparation using inkjet printing.
• To establish robust and precise colorimetric measurements using digital imaging and the HSV color space.

Main Methods:

• Utilized inkjet printing for reproducible preparation of sensing membranes.
• Employed digital camera imaging to capture array color data.
• Applied the H coordinate of the HSV color space as the primary analytical parameter.
• Developed a two-stage neural network for analyzing complex ion mixtures.

Main Results:

• Achieved highly reproducible sensing membranes via inkjet printing.
• Demonstrated robust and precise measurements using the H coordinate of the HSV color space.
• Successfully identified 13 different metal ions.
• Accurately determined mixtures containing up to 5 metal ions.

Conclusions:

• Inkjet printing significantly enhances the reproducibility and discriminatory power of colorimetric sensing arrays.
• Digital imaging combined with HSV color space analysis offers a precise method for colorimetric measurements.
• The developed neural network approach provides high accuracy for identifying metal ions and their mixtures.