Cytotoxicity Assessment Using Label-Free Impedimetric Biosensing: Comparative Evaluation with Conventional Assays

Area of Science:

• Environmental Science
• Biotechnology
• Toxicology

Background:

• Quantitative and sensitive monitoring of chemical stress effects is globally needed.
• Existing in vitro cytotoxicity assays have limitations in sensitivity and early detection.
• Organophosphorus pesticides, such as diazinon, pose significant environmental and health risks.

Purpose of the Study:

• To introduce and evaluate a rapid, non-destructive impedimetric biosensor for assessing chemical stress.
• To compare the sensitivity and effectiveness of the novel biosensor against established in vitro cytotoxicity assays.
• To demonstrate the biosensor's capability in detecting early toxicological events caused by pesticides.

Main Methods:

• Development of a cell-based impedimetric biosensor utilizing in vitro cell systems.
• Exposure of the biosensor to diazinon, an organophosphorus pesticide, as a model chemical.
• Assessment of cell density and viability using light microscopy.
• Electrochemical impedance spectroscopy (EIS) for measuring impedance changes in response to diazinon exposure.

Main Results:

• Light microscopy confirmed consistent cell density and viability on the biosensor electrodes.
• EIS analysis showed a linear, concentration-dependent decrease in impedance upon diazinon exposure.
• The impedimetric biosensor exhibited significantly lower effective concentrations (EC50 = 0.079mM, EC20 = 0.012mM, EC10 = 0.006mM) compared to conventional assays.
• The biosensor detected earlier toxicological events than standard cytotoxicity tests.

Conclusions:

• The developed cell-based impedimetric biosensor offers a sensitive and rapid method for monitoring chemical stress.
• This label-free platform enables non-destructive assessment of the effects of aquatic contaminants.
• The biosensor's ability to detect earlier toxicological events provides a significant advantage over conventional methods.