Lonophore-based lithium ion film optode realizing multiple color variations utilizing digital color analysis

Area of Science:

• Analytical Chemistry
• Materials Science
• Sensor Technology

Background:

• Digital color analysis (DCA) offers quantitative insights and aids in developing visual colorimetry sensors.
• Virtual simulations based on digital color information can predict sensor performance.
• Developing sensitive and visually distinct sensors for ion detection remains a key challenge.

Purpose of the Study:

• To design and prepare a color-changeable film sensor (film optode) for accurate lithium ion determination.
• To achieve a clear and predictable visual color variation for lithium ion sensing.
• To validate the sensor's performance using digital color analysis and virtual simulations.

Main Methods:

• Fabrication of a plasticized PVC membrane film optode incorporating two lipophilic dyes (KD-C4, KD-M11) with distinct properties.
• Inclusion of a lithium ionophore (TTD14C4) and a lipophilic anionic additive in the PVC membrane.
• Digital color analysis (DCA) for virtual simulation of color variation using L*a*b* coordinates and experimental validation.

Main Results:

• The developed film optode demonstrated a distinct color change from red to blue across a lithium ion concentration range of 10⁻⁶–1 M.
• The observed color variation (red → orange → yellow → green → blue) closely matched the virtual simulation results obtained via DCA.
• The molecular ratio of KD-C4/KD-M11 at 3:1 was optimized for optimal color transition.

Conclusions:

• The novel film optode, utilizing mixed lipophilic dyes, provides a reliable method for visual and quantitative determination of lithium ions.
• Digital color analysis serves as an effective tool for simulating and predicting the colorimetric response of chemical sensors.
• This approach offers a promising platform for developing advanced visual sensors for various analytical applications.