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Precise, High-throughput Analysis of Bacterial Growth
Published on: September 19, 2017
Measuring bacterial growth by refractive index tapered fiber optic biosensor
Mohammad Ismail Zibaii1, Alireza Kazemi, Hamid Latifi
1Shahid Beheshti University, Evin, Tehran, Iran.
Journal of Photochemistry and Photobiology. B, Biology
|September 7, 2010
Summary
This study demonstrates a novel fiber optic biosensor for real-time monitoring of Escherichia coli (E. coli) growth. The biosensor accurately tracks bacterial population changes by measuring alterations in optical properties, offering rapid detection capabilities.
Area of Science:
- Biomedical Engineering
- Optical Sensing
- Microbiology
Background:
- Real-time monitoring of bacterial growth is crucial for understanding infection dynamics and developing effective treatments.
- Traditional methods for bacterial quantification can be time-consuming and labor-intensive.
- Fiber optic biosensors offer a promising platform for sensitive and rapid detection of biological analytes.
Purpose of the Study:
- To develop and validate a single-mode tapered fiber optic biosensor for real-time monitoring of Escherichia coli (E. coli) K-12 growth.
- To compare the performance of the fiber optic biosensor with traditional colony counting methods.
- To explore the potential of this novel sensing method for rapid bacterial analysis.
Main Methods:
- Fabrication of single-mode tapered fiber optics using a heat-pulling method (waist diameter 6-7μm, length 3mm).
- Immobilization of E. coli K-12 onto the tapered fiber surface using Poly-l-Lysine.
- Real-time monitoring of bacterial growth by measuring changes in optical throughput via transmission of a 1558.17nm distributed feedback (DFB) laser.
- Validation of sensor results by comparing with the colony counting method.
Main Results:
- The fiber optic biosensor successfully monitored E. coli K-12 growth in real-time.
- Bacterial population growth led to an increase in the refractive index of the tapered region, affecting the evanescent field and optical throughput.
- Sensor measurements showed good correlation with results obtained from the colony counting method.
- The developed sensor demonstrated sensitivity to changes in bacterial surface density.
Conclusions:
- A single-mode tapered fiber optic biosensor provides a viable method for real-time, label-free monitoring of bacterial growth.
- This technology offers a promising alternative to conventional methods for rapid bacterial detection and quantification.
- The biosensor has potential applications in areas such as food safety, environmental monitoring, and clinical diagnostics.
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