Grantee Research Project Results

Final Report: Handheld MEMS-Based Detector of Toxins and Toxigenic Organisms Indicative of Harmful Algal Bloom

EPA Contract Number: EPD07057
Title: Handheld MEMS-Based Detector of Toxins and Toxigenic Organisms Indicative of Harmful Algal Bloom
Investigators: Hobson, Stephen T
Small Business: Seacoast Science, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2007 through August 31, 2007
Project Amount: $69,971
RFA: Small Business Innovation Research (SBIR) - Phase I (2007) RFA Text |  Recipients Lists
Research Category: SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)

Description:

Real-time detection, identification, and quantification of toxins and toxigenic organisms indicative of cyanobacteria harmful algal blooms (cyanoHABs) in drinking water are vital data for public safety administrators. Different biomolecule–transition metal conjugates (bio-tm-C) were mapped onto a sensor array using a proprietary inkjet deposition process. The selective and non selective binding of the antigen (toxin) with the bio-tm-C array resulted in a change in dielectric properties of the sensor matrix, which was detected and processed. The nature of the proposed system will allow for rapid analysis (≤ 10 minutes), immediate display, and optional linking (remotely or directly) of the signal to a computer.

Summary/Accomplishments (Outputs/Outcomes):

• Surface immobilization and characterization of bio-tm-C on current MEMS IDT chip—Deposited bio-tm-C onto MEMS IDT sensor using an ink jet system. Viability and specificity of the biomolecule were probed using confocal microscopy in conjunction with fluorescently labeled analytes.
• Redesign of MEMS sensor for liquid testing—Designed, sent for fabrication, and tested novel MEMS IDT sensor chip for direct detection of analytes in liquid.
• Liquid testing of prototype MEMS liquid sensor—Direct detection of organic compounds, biological macromolecules, fluorescent tags, proteins, and toxins.
• Pattern recognition data collection and algorithm development—Algorithm developed using multisensor data for application of detection in liquid.

Conclusions:

This Phase I Small Business Innovation Research project extended Seacoast Science’s MEMS- based chemicapacitive sensor array from the detection of analytes in the vapor phase to the direct detection of analytes in aqueous solution. This vital technological hurdle was accomplished by the successful deposition of transition metal nanoparticle-biomolecule conjugates onto a novel redesigned MEMS IDT chemicapacitive sensor platform, followed by exposure of the sensor to the analytes in water or buffer. Impressive limits of detection were obtained for small organic molecules (≤ 1 mM), proteins (~ 1 nM), and cyanoHAB toxins (~5 μM).

Supplemental Keywords:

small business, SBIR, EPA, harmful algal blooms, cyanobacteria, cyanoHABs, MEMS-based sensor technology, water quality; point of care diagnostics, water security,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Water, algal blooms, Environmental Monitoring, early warning capabilities, drinking water, MEMS based sensor, real time monitoring