Real-Time Detection of Yeast Growth on Solid Medium through Passive Microresonator Biosensor

Area of Science:

• Biosensor Technology
• Microbial Monitoring
• Integrated Passive Device (IPD) Technology

Background:

• Real-time measurement of microbial growth is crucial for various scientific and industrial applications.
• Existing methods may lack sensitivity, speed, or continuous monitoring capabilities.
• Integrated Passive Device (IPD) technology offers a platform for novel sensor fabrication.

Purpose of the Study:

• To develop and validate a novel biosensor using IPD technology for real-time measurement of microbial growth.
• To demonstrate the biosensor's performance using yeast (Pichia pastoris) as a model organism.
• To analyze the relationship between biosensor electrical parameters and yeast growth dynamics.

Main Methods:

• Fabrication of a biosensor utilizing an interdigital capacitor and helical inductive structure on an IPD platform.
• Incorporation of air bridges to enhance the electric field strength.
• Real-time monitoring of yeast growth on solid media at a 1.84 GHz operating frequency.
• Analysis of capacitance and resonant amplitude changes correlating with yeast colony height and proliferation.

Main Results:

• The biosensor detected changes in electrical parameters (capacitance, resonant amplitude) induced by yeast growth.
• Resonant amplitude showed continuous variation from 24 to 72 hours, correlating with yeast vertical growth (max change 0.21 dB).
• Measurement data exhibited a strong fit with the Gompertz curve and a linear relationship with time (R²=0.9844) between 24-72 hours.

Conclusions:

• The IPD-based biosensor is effective for real-time monitoring of microbial proliferation.
• The biosensor demonstrates suitability for tracking yeast growth dynamics.
• This technology holds significant potential for applications in microbial detection and analysis.