A Simple Contactless High-Frequency Electromagnetic Sensor: Proof of Concept.

Area of Science:

• Electrical Engineering
• Analytical Chemistry
• Biosensing

Background:

• Traditional analytical methods often require complex equipment and sample preparation.
• There is a need for rapid, cost-effective, and versatile sensing technologies for diverse applications.

Purpose of the Study:

• To develop and validate a simple, inexpensive sensor device based on an inductance coil for analyzing liquid samples.
• To demonstrate the sensor's capability in distinguishing substances, quantifying concentrations, and identifying biological cultures.

Main Methods:

• A sensor device was constructed using an inductance coil connected to a high-frequency electric field generator.
• Liquid samples were placed within the inductance coil, acting as the core.
• Changes in high-frequency electric current properties (conductivity, dielectric constant, capacitance) were measured and analyzed using chemometric tools.

Main Results:

• The sensor successfully distinguished between substances with varying physical and chemical properties.
• A linear response was observed for ion concentration in aqueous solutions across a broad range (10⁻³ M to 10⁻¹ M).
• Fat content in milk and cream was quantified with approximately 2% accuracy, and bacterial and cell line cultures were differentiated.

Conclusions:

• The developed inductance coil sensor offers a fast, contactless, and cost-effective method for liquid analysis.
• The sensor shows significant promise for diverse applications in chemical analysis, food science, and biotechnology.
• Further development could lead to widespread adoption of this versatile sensing technology.