MICROWAVE BIOSENSORS for SINGLE-CELL DIELECTRIC CHARACTERIZATION: a REVIEW.

Area of Science:

• Biophysics
• Microwave Engineering
• Microsystem Design

Background:

• Cellular dielectric properties vary with structure, function, and molecular composition.
• Assessing these properties offers label-free, non-invasive methods for disease diagnosis and cell analysis.
• Dielectric dispersion (α-, β-, γ-regimes) relates to cellular parameters like capacitance, conductivity, and hydration.

Purpose of the Study:

• To review the fundamentals and applications of microwave biosensors for single-cell analysis.
• To explore how electromagnetic interactions reveal cellular parameters.
• To discuss sensing platforms and the role of dielectrophoresis (DEP) in hybrid systems.

Main Methods:

• Review of physical principles of dielectric dispersion and equivalent circuit models.
• Examination of sensing platforms: transmission line sensors, capacitive electrode arrays, resonant structures.
• Discussion of dielectrophoresis (DEP) for manipulation and sensing in hybrid systems.

Main Results:

• Microwave biosensors enable extraction of cellular parameters (membrane capacitance, cytoplasmic conductivity, intracellular hydration).
• Various sensing platforms (transmission lines, electrodes, resonators) have distinct strengths and weaknesses for single-cell sensing.
• Hybrid DEP-microwave systems combine manipulation and high-frequency dielectric readout for enhanced analysis.

Conclusions:

• Microwave biosensors offer high-resolution, real-time single-cell interrogation.
• These technologies integrate microwave engineering, biophysics, and microsystem design.
• Future dielectric biosensors will advance single-cell diagnostics, drug screening, and functional phenotyping.