Development of SPR Imaging-Impedance Sensor for Multi-Parametric Living Cell Analysis

Area of Science:

• Biomedical Engineering
• Cell Biology
• Sensor Technology

Background:

• Label-free, real-time monitoring of living cells is crucial for basic research and clinical diagnosis.
• Existing methods often lack multi-parametric analysis capabilities for cellular functions.
• Developing integrated sensor platforms is essential for comprehensive cell analysis.

Purpose of the Study:

• To develop a novel SPRI-impedance sensor for simultaneous, label-free detection of refractive index (RI) and impedance changes in living cells.
• To investigate the sensor's capability for real-time monitoring of cellular responses to stimuli.
• To explore the potential of this technique for clinical applications like allergy diagnosis.

Main Methods:

• Development of a SPRI-impedance sensor chip with comb-shaped electrodes.
• Culturing rat basophilic leukemia (RBL)-2H3 cells on the sensor chip.
• Stimulating RBL-2H3 cells with dinitro-phenol-conjugated human serum albumin (DNP-HSA) antigen.
• Simultaneous monitoring of RI and impedance changes using the developed sensor.

Main Results:

• The SPRI-impedance sensor successfully detected label-free, real-time cellular reactions, including degranulation and morphological changes in RBL-2H3 cells.
• Impedance changes associated with cell activation were observed in the 1 kHz-1 MHz frequency range.
• Simultaneous monitoring of RI and impedance changes derived from living cells was achieved.

Conclusions:

• A new technique using a comb-shaped electrode sensor chip enables simultaneous monitoring of both impedance and RI from living cells.
• This method offers a powerful tool for elucidating complex cellular functions impacting RI and impedance.
• The developed technique holds promise for medical applications, including accurate clinical diagnosis of type I allergy.