Grantee Research Project Results
Final Report: Rapid, Specific, Sensor System for Pathogens in Water
EPA Contract Number: 68D02038Title: Rapid, Specific, Sensor System for Pathogens in Water
Investigators: Tiernan, Timothy C.
Small Business: TPL Inc.
EPA Contact: Richards, April
Phase: I
Project Period: April 1, 2002 through September 1, 2002
Project Amount: $69,046
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , SBIR - Monitoring , Small Business Innovation Research (SBIR)
Summary/Accomplishments (Outputs/Outcomes):
The specific technical objectives for Phase I were to:
· Design and fabricate APM sensors suitable for use with protein probe molecules.
· Fabricate the APM sensor substrates using photolithography to produce the interdigital transducers, and CVD to form a primer layer on the APM surface for binding the protein probes to the sensor.
· Develop the biosensor chemistry for use with the sensors.
· Design and fabricate the prototype instrumentation system electronics and software.
· Develop test protocols for the evaluation of the APM sensor substrates and protein probe chemistry.
· Conduct a prototype performance testing and comparison study.
· Submit reports to the U.S. Environmental Protection Agency.
The first four objectives listed above were successfully completed during the Phase I research project, and the fifth objective was partially completed. However, definitive measurement of pathogen detection was not achieved during this project.
Conclusions:
Many advances have been made in developing TPL's sensor system for pathogens in water. These include:
· Sensing on the opposite side of the quartz sensor, the side opposite the interdigitated radio frequency transmitting and receiving assemblies.
· Sensing in multiple types of fluid.
· Significantly reducing the randomly generated noise associated with the acoustic wave sensor with a damping system.
· Engineering the damping system to significantly reduce and eliminate electronic and thermal stability control systems.
· Engineering the damping system to be an integral part of a sealed biochamber.
· In the latter phases of the project, shielding the entire assembly from outside electromagnetic interference to obtain a frequency drift of less than ± 0.3 Hz per 10 sec.
In one of its DNA research programs (see Figure 1), TPL was able to obtain significant mass loading, and thus, significant frequency shifts of the sensor by changing just a few simple protocols in the test process. It is anticipated that the same will be true with TPL's research in pathogen detection using antibodies.
The obvious challenge that remains is to develop one or more techniques or simple changes in protocols for binding antibodies to the quartz surface through some intermediate medium, and then to bind pathogens to those antibodies. There are several known protocols for binding antibodies to glass; it is a matter of time and persistence until TPL transfers those techniques and protocols to a moving quartz surface. An obvious, straightforward technique would be to hold the quartz surface stationary until binding takes place. Until recently, this presented a problem, but recent advances may make the incurred frequency shifts insignificant when very large frequency shifts are realized by changing some basic protocols in the test procedures.
In the near future, TPL hopes to present test results indicating that this is a viable, rugged, and robust technology that should obtain further funding, not just for specific pathogen detection, but also as a broad-spectrum pathogen detection system.
Figure 1. 255 base pairs positive PCR product target binding with 22 mere pair oligonucleotide (oligo) probe attached to quartz sensor in biochamber (test results from U.S. Army Contract # DAAD130C0005, Laser-Coupled, Multi-Site Microfabrication-Based Platform). This plot was the result of mass loading TPL's acoustic wave sensor with 262 pair DNA product bonding to 22 pair oligo target attached to the quartz acoustic wave sensor. The actual bonding of the 262 DNA pair to the target oligos occurs approximately between 16:29:07 and 17:00:59. The sensors used in these tests were the same type of sensors used in the tests for this report.
Supplemental Keywords:
sensor, pathogen water, Cryptosporidium, surface acoustic wave, SAW, bioprobe, acoustic plate mode device, photolithography, chemical vapor deposition, DNA, quartz, ligand, microfabricated array, SBIR, small business., RFA, Scientific Discipline, Water, Ecosystem Protection/Environmental Exposure & Risk, Monitoring/Modeling, Analytical Chemistry, Environmental Monitoring, Environmental Engineering, Drinking Water, Engineering, Chemistry, & Physics, monitoring, wastewater treatment, pathogens, real time analysis, aquatic organisms, contaminant transport, contaminants, field portable systems, field portable monitoring, human health effects, field monitoring, detection system, cryptosporidium , biomonitoring, stormwater, municipal wastewater, environmental chemistry, microbial risk management, water quality, field detection, emerging pathogens, water contaminants, antibodies, drinking water contaminants, drinking water treatment, human health, real-time monitoring, drinking water systemThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.