Biosensors Developed for Detection of Gram-negative Bacteria Species

Student: Rudy Acosta

Degree: M.S., July 2021

Major Professor: Dr. Z. Ryan Tian

Research Area(s):

Physical & Chemical Sensors

Biological Materials & Processes

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Background/Relevance

  • Current methods in the market for bacteria detection are time consuming, expensive, user unfriendly, and likely to produce false negative/positive results more often than desired.
  • Compact and inexpensive bacterial sensors have been long-overdue to industry, homeland security, and clinics.

Innovation

  • By modifying the radio frequency identification (RFID) tags, various bacterial strains can be identified by monitoring the RFID signals in real-time and single-cell sensitivity at low-cost.

Approach

  • Deposit rGO-TiO2/polymer nanocomposite thin films (sensing layer) on the surface of an RFID tag’s hot spot.
  • Using the modified tag to detect the bacteria at various concentrations.
  • Integrating the tag with a custom-made flow cell for detecting bacteria e.g. bacillus B (see below)

Key Results

  • As shown below, there is a linear correlation between the tag’s impedance and number of bacterial cells.
  • Our new sensory nanocomposites made the tag able to show different signals for every bacterium at various concentrations.

Conclusions and Future Work

  • Bacteria appear to have their characteristic impedance and frequency patterns when interacting with the RFID sensor.

  • Further testing will be conducted to further improving the detection of bacterial cells in a flow cell.