An endothelial cell compatible biosensor fabricated using optically thin indium tin oxide silicon nitride electrodes.

Area of Science:

• Biomedical Engineering
• Materials Science
• Cell Biology

Background:

• Microimpedance biosensors are crucial for real-time cellular analysis.
• Indium tin oxide (ITO) offers unique optical and electrical properties for biosensing applications.
• Developing biocompatible and optically transparent biosensors is essential for in situ cellular studies.

Purpose of the Study:

• To fabricate and characterize an optically thin, endothelial cell-compatible indium tin oxide (ITO) microimpedance biosensor.
• To evaluate the biosensor's performance for monitoring cellular attachment, spreading, and drug responses.
• To demonstrate the utility of the biosensor for dynamic cellular impedance studies with optical imaging.

Main Methods:

• Fabrication of ITO microelectrodes with a silicon nitride (Si(3)N(4)) insulating layer.
• Monitoring cellular impedance of porcine pulmonary artery endothelial cells (PPAECs) using a lock-in amplifier.
• Conducting frequency-dependent (10-100 kHz) and time-dependent (5.62 kHz) impedance measurements.
• Assessing cellular response to Cytochalasin D.

Main Results:

• The ITO-Si(3)N(4) microelectrodes demonstrated consistent and repeatable impedance measurements for PPAEC attachment and spreading.
• The biosensor exhibited robustness, recyclability, ethanol resistance, and high optical transmittance.
• Optical access was maintained for dynamic cellular attachment imaging.
• Time-dependent impedance measurements effectively showed cellular responses to Cytochalasin D.

Conclusions:

• The developed ITO-Si(3)N(4) microimpedance biosensor is suitable for endothelial cell culture and monitoring.
• The biosensor's optical transparency and robustness make it ideal for dynamic cellular studies.
• This configuration facilitates real-time impedance analysis and optical imaging for drug efficacy studies.