Near-real Time, Highly Sensitive and Selective Field Deployable Biosensor for Cyanotoxins and Cyanobacteria Using both Antibodies and DNA-signaturesEPA Grant Number: R833829
Title: Near-real Time, Highly Sensitive and Selective Field Deployable Biosensor for Cyanotoxins and Cyanobacteria Using both Antibodies and DNA-signatures
Investigators: Mutharasan, R.
Institution: Drexel University
EPA Project Officer: Klieforth, Barbara I
Project Period: June 10, 2008 through March 31, 2011 (Extended to September 30, 2013)
Project Amount: $599,999
RFA: Development and Evaluation of Innovative Approaches for the Quantitative Assessment of Pathogens and Cyanobacteria and Their Toxins in Drinking Water (2007) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
The overall goal of the proposed research is to develop piezoelectric-excited millimeter-sized cantilever sensors (PEMC) for cyanotoxins in source, finished and system waters that measures in a field-deployable format and rapidly in 15 minutes so that cyanotoxin(s) hazard and management decisions can be made in a timely fashion. The cantilever sensors are of unique design and are the result of development in the PI’s lab over the past 5 years. PEMC’s significant advantage is the use of label-free reagents and a proposed simple measurement format. PEMC sensors exhibit high sensitivity that >femtograms per liter (10-15 g/L; parts per quintillion) cyanotoxin concentration would be measurable directly by dipping into a few milliliters water samples. PEMC sensors are not the fragile AFM-like microcantilevers, but are mechanically robust millimeter-sized resonant mode cantilevers that exhibit high-order mode that measures mass changes at femtogram (10-15 g) level under liquid immersion and flow conditions.
There are four objectives centered on the cyanotoxin and cyanobacteria detection. These are: (1) Develop a batch cyanotoxin measurement method for field use preserving the previously achieved detection sensitivity of PEMC sensors, and validate measurements with current methods (ELISA and HPLC/MS). (2) Develop a new rapid method for anatoxin-a and anatoxin-a(s) in source and finished water matrices based on an available, but weakly binding, antibody and an enzyme-binding assay. (3) Develop a rapid DNA-based assay for cyanobacteria. (4) Test lake water samples analyzed by US Geological Survey (USGS) using the method developed in the first three objectives.
Antibodies to cyanotoxins will be immobilized on sensor surface and the sensor will be exposed to toxin containing water (river, finished and system waters) to obtain sensor response. Selectivity is expected to be achieved due to the previously demonstrated property of the vibrating sensor. We will collaborate with a cyanotoxin specialty company, Abraxis, LLC, which has developed antibodies against algal toxins (cylindrospermopsin, microcystins, saxitoxins and others) and currently markets ELISA kits. PEMC sensor response will be compared in parallel experiments conducted at higher concentration carried out at Abraxis. Using a model cyanobacterium (Microcystis aeruginosa (LB 2385)) 2-hour laboratory-based assay using PEMC sensor methodology will be developed with the mcy gene family as the recognition element. In the final phase of the project we will test the methods developed in this study with lake water samples analyzed by the US Geological Survey and compare PEMC sensor results with current methods - ELISA and HPLC/MS.
(1) A new rapid sensor-based method for measuring cyanotoxins in source, finished and system water will be developed. (2) A new 2-hour sensor-based detection for cyanobacteria based on the mcy gene family will be developed. (3) A new rapid sensor-based method for measuring anatoxin-a and anatoxin-a(s) will be developed.