Volatile organic compound specific detection by electrochemical signals using a cell-based sensor.

Area of Science:

• Biomedical Engineering
• Environmental Science
• Analytical Chemistry

Background:

• Volatile organic compounds (VOCs) pose health risks, necessitating sensitive detection methods.
• Oxidative stress is implicated in VOC cytotoxicity, but its role requires further elucidation.
• Existing methods for VOC detection and toxicity assessment can be complex and time-consuming.

Purpose of the Study:

• To develop a cell-based in vitro exposure system for assessing the role of oxidative stress in VOC-induced cytotoxicity.
• To create a novel immobilized cell-based sensor for electrochemical detection of VOCs.
• To correlate VOC toxicity with cellular responses, including nitric oxide generation and gene expression.

Main Methods:

• Fabrication of thin films using cysteine-terminated synthetic oligopeptides for HeLa cell immobilization on a gold substrate.
• Utilizing surface plasmon resonance (SPR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) for sensor characterization and cell immobilization verification.
• Exposure of immobilized cells to VOCs (benzene, toluene, xylene, chlorobenzene) and monitoring of electrochemical signals, SPR changes, nitric oxide generation, and gene expression (p53, NF-kappaB).

Main Results:

• Successful immobilization of human epithelial HeLa cells on a gold substrate using a self-assembly technique.
• Demonstrated VOC-specific electrochemical signals and changes in SPR angle upon exposure.
• Established a correlation between VOC toxicity, nitric oxide generation, and electrochemical impedance spectroscopy (EIS) changes.
• Observed p53 and NF-kappaB downregulation linked to VOC-induced growth inhibition.

Conclusions:

• The developed cell immobilization method and VOC-specific electrochemical signals enable the construction of a cell microarray for onsite VOC monitoring.
• The system effectively assesses the role of oxidative stress in VOC-induced cytotoxicity.
• This approach offers a promising platform for environmental monitoring and toxicological studies of VOCs.