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Final Report: Development of a Multianalyte Biosensor Instrument
EPA Contract Number: 68D70028Title: Development of a Multianalyte Biosensor Instrument
Investigators: Schmidt, John C.
Small Business: Environmental Technologies Group Inc.
EPA Contact:
Phase: I
Project Period: September 1, 1997 through March 1, 1998
Project Amount: $69,966
RFA: Small Business Innovation Research (SBIR) - Phase I (1996)
Research Category: SBIR - Monitoring and Analysis , Ecological Indicators/Assessment/Restoration
Description:
The purpose of this project was to reduce the cost and turnaround time of several types of environmental field measurements. Recent research indicates that biosensors have the potential to fulfill field-screening requirements for volatile and nonvolatile organics, metals, and other ions. However, versatile commercial instruments based on biosensors are not yet available. The main barrier to the commercialization of biosensors is the diversity of field-screening applications. More than 600 chemical compounds have been identified at hazardous waste sites. Therefore, the potential market for any one application is relatively small, and not likely to justify the development cost of a biosensor instrument.One way to overcome this problem is to develop a biosensor instrument that is capable of analyzing many different analytes. The major objective of this project was to develop a biosensor instrument that is capable of detecting many different analytes in the field in real time and at a cost that is significantly less than that of current laboratory analyses.
Summary/Accomplishments (Outputs/Outcomes):This investigation developed and proved the feasibility of the Biolyzer 1000TM, an electrochemical biosensor instrument capable of detecting numerous organics, metals, and several other ions. The Biolyzer 1000TM system consists of a reuseable instrument and several different disposable sensors (see Figures 1 and 2). The instrument is a battery-operated, hand-held device that contains an interface that accepts the disposable sensors. The instrument also contains a liquid crystal display (LCD) that provides instructions to the analyst and reports the results of the analysis in the appropriate units. The instrument is capable of interfacing with several different types of disposables, each of which performs a different analysis. The instrument recognizes the analysis that is being performed by reading the information on a small calibration chip (shipped with the disposable sensors), which is inserted into the instrument prior to the analysis. Using the information on the calibration chip, the microprocessor in the instrument is able to set the electrochemical parameters to the appropriate values and calculate the analyte concentrations using the calibration factors previously measured in the factory. The patented disposable sensor contains a polypropylene housing, screen-printed electrode, sample cup, and reagent ampoule.
The disposable design eliminates the need to measure samples and handle reagents in the field. Operation of the system consists of several simple steps:
? Add sample to the sample cup, and close the cap (the cup meters the correct amount of sample).
? Screw the cup into the sensor housing. A prong in the housing displaces the sample cup bottom, which releases the sample into the sensor housing.
? Flex the sensor to break the reagent ampoule, which releases the reagent.
? Shake the sensor to mix the sample and reagent, and insert the sensor into the instrument.
Because sensors were available for several metals (copper, lead, cadmium, and
zinc) from a previous program, this program concentrated on the development of a
biosensor for phenols. The phenol biosensor contains a graphite working
electrode that is coated with tyrosinase, an enzyme that specifically converts
phenols to quinones that can be detected electrochemically. The precision,
sensitivity, and selectivity of the biosensor was optimized. The optimization
process involved testing several different types of graphite ink, developing an
automated method of applying the tyrosinase enzyme to the electrode, optimizing
the enzyme layer thickness and printer application pattern, and optimizing the
electrochemical analysis parameters. The optimized sensor was calibrated with
four phenols in the 0-2 ppm range, and the coefficient of variation was shown to
be approximately 10 percent. When eight different natural water samples from
five parts of the United States were spiked with 2 ppm phenol, the yield ranged
from
83-105 percent, demonstrating that the biosensor is not vulnerable to
false-negative results due to materials normally found in natural water. A
shelf-life test was performed, and showed that the sensor can be stored at room
temperature for approximately 6 months before significant sensitivity changes occur.
Environmental Technologies Group, Inc. (ETG) originally planned to sell the Biolyzer 1000TM system as part of its new environmental product line. However, ETG was purchased by Smiths Industries during this SBIR project and has been directed to focus on its military businesses. Therefore, ETG has negotiated two agreements to commercialize the Biolyzer 1000TM system:
? The first agreement sells the Biolyzer 1000TM system rights to a small sensor manufacturer in return for an up-front payment, evaluation funding, and significant royalties on sensor and instrument sales. This sensor company has a relationship with a large laboratory equipment manufacturer to produce the instrument and sell the Biolyzer 1000TM system through its catalog.
? The second agreement funds ETG to develop additional sensors.
ETG has raised a total of $96,924 for the system evaluation and sensor development efforts, and expects to realize annual royalties in excess of the EPA grant amount within 2 years.
Supplemental Keywords:monitoring, engineering, chemistry, multianalyte, Biolyzer 1000TM system. , Ecosystem Protection/Environmental Exposure & Risk, Water, Air, Scientific Discipline, RFA, Engineering, Chemistry, & Physics, Chemical Engineering, Civil/Environmental Engineering, Chemistry, Environmental Engineering, Environmental Chemistry, Monitoring/Modeling, multianalyte biosensor field screening instrument (MBFI), multianalyte biosensor, biosensors, multi-analyte systems
Progress and Final Reports:
Original Abstract