Development of Microalgae Biosensor Chip by Incorporating Microarray Oxygen Sensor for Pesticides Sensing

Area of Science:

• Environmental Science
• Biotechnology
• Analytical Chemistry

Background:

• Pesticide contamination poses a significant threat to water quality and ecosystem health.
• Developing sensitive and cost-effective biosensors is crucial for effective water monitoring.
• Microalgae-based biosensors offer a promising approach for detecting environmental pollutants.

Purpose of the Study:

• To develop and validate a microalgae biosensor chip for sensitive pesticide detection.
• To assess the biosensor's performance against a range of common pesticides.
• To evaluate the potential of this biosensor for routine water quality monitoring.

Main Methods:

• Immobilized *Pseudokirchneriella subcapitata* microalgae biofilm was patterned onto dye-spotted microarray slides using microcontact printing.
• Fluorescence intensity changes, indicative of photosynthetic oxygen production, were monitored using an inverted fluorescent microscope.
• Inhibition of oxygen generation rate was calculated based on fluorescence intensity variance before and after pesticide exposure.

Main Results:

• The biosensor demonstrated high sensitivity to diuron (1 ppb detection limit) and moderate sensitivity to simetryn, simazine, and atrazine (10 ppb detection limits).
• The biosensor was insensitive to mefenacet and pendimethalin among the tested pesticides.
• Calibration curves showed a clear correlation between pesticide concentration and inhibition of photosynthetic activity.

Conclusions:

• The developed microalgae biosensor chip offers a simple, low-cost, and effective method for detecting specific pesticides in water.
• This technology holds significant potential for regular environmental water quality monitoring, particularly for pesticide contamination.
• Further research could expand the range of detectable pesticides and optimize biosensor performance.