New biosensors for detection of bacteria

Student: Rudy Acosta

Degree: M.S., December 2020

Major Professor: Dr. Z. Ryan Tian

Research Area(s):

Physical & Chemical Sensors

Biological Materials & Processes

View Research Quadslide


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


  • By modifying the radio frequency identification (RFID) tags, volatile organic compounds (VOC) of different bacteria can be identified by monitoring the RFID signals in real-time.


  • 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-generated VOCs
  • In parallel, integrating the tag with a custom-made flow cell for detecting bacteria e.g. salmonella, E. coli, bacillus B (see below)

Key Results

  • As shown below, there could be a linear correlation between the tag signal’s intensity and the target analyte’s descending concentration.
  • Our new sensory nanomaterial made the tag to show different signals for each of the VOCs at various concentrations.

Conclusions and Future Work

  • When interacting with the RFID sensor, bacteria-generated VOCs each shows a characteristic impedance and frequency.

  • Further testing will be conducted to find the limit of detection (LOD) of bacterial cells in a new microfluidic device.