Progress 08/01/19 to 03/31/20

Outputs
Target Audience:The target audience for this report is: Steven J. Thomson, Ph.D. Acting Division Director, Agricultural Systems National Program Leader USDA-NIFA 6501 Beacon Drive 5NW054, 5th Floor Kansas City, MO 64133 Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Our scientists have learned important skills in electrochemical biosensors that enable a general platform for small molecule detection. In Phase II they will be able to generate sensors for all pesticides and herbicides of commercial interest. On the business front, the PI (CEO) has learned much about the market needs for this product, fund raising and new product introduction. How have the results been disseminated to communities of interest?Yes, we plan to soon publish in peer-reviewed journals. Our initial successes have already been shared on our website and in several conference proceedings. What do you plan to do during the next reporting period to accomplish the goals?This is an interim report. The results have been conveyed to Dr. Steven Thomson. The Phase I SBIR project continues until 3/31/2020. We are currently preparing the Final Technical Report as well as the Phase II proposal and Commercialization Plan.

Impacts
What was accomplished under these goals? During this Phase I SBIR effort, we continued to survey farmers, studied the literature, and did our own research as to the necessary limits of detection (LOD) for any sensor designed to detect dicamba at a potentially damaging level to non-resistant soybeans. It quickly became clear that a lateral flow approach (pregnancy-type test) would never be sensitive enough to meet the market needs. We therefore quickly pivoted to the development of a quantitative, much more sensitive, electrochemical "aptasensor" approach. In this approach, we use a portable, handheld potentiostat and disposable electrodes functionalized with aptamers selected to detect dicamba. The aptamers are immobilized on the gold, screen-printed electrodes using a thiol on one end of the aptamer. On the other end of the aptamer is a redox reporter - methylene blue (MB). Binding to dicamba changes the electron transfer efficiency of the MB to the electrode. Currently we have developed sensors with a sensitivity (LOD) of 71 ppb which is highly relevant to crop protection. In Phase II, we expect to improve this LOD by at least one order of magnitude.

Publications

Progress 08/01/19 to 03/31/20

Outputs
Target Audience:Opportunity Herbicides, since their advent in the early 1950's, have been a tremendous and invaluable tool to production agriculture. Since that time the agricultural crop production market has changed considerably due to a number of technological innovations including the introduction of genetically modified organisms (GMO) crops. Although surrounded by some controversy, the ability to genetically engineer certain seeds to be resistant to specific herbicides or pesticides has revolutionized the market for several of the world's most important food products. It is estimated that nearly ninety percent of all corn and soybeans now grown worldwide are GMO's. Project Objectives This project aims to develop an important tool which is currently non-existent. Specifically, during Phase I, we developed a prototype electrochemical aptamer-based sensor or "aptasensor" for the herbicide dicamba. Dicamba has been used for years, however the recent development of dicamba-resistant and dual-resistant GMO soybeans to dicamba and glyphosate have left farmers with insufficient tools to protect sensitive fields from sprayer contamination or herbicide drift. Our approach is highly innovative in that it utilizes a relatively new form of test reagent - DNA aptamers and novel reporting methods which will enable the farmer to quickly and inexpensively assay spray tanks and equipment as well as arbitrary water samples in the field. Anticipated Results and Commercial Applications By the end of the Phase II effort, we will have established a novel platform for routine field testing of arbitrary water samples for dicamba. The test will have a sensitivity relevant to monitoring spray equipment for residual herbicide which could devastate sensitive non-engineered crops. In addition to a handheld endpoint test using the electrochemical reader (much like a personal glucose meter), we are also in talks with major farm equipment manufacturers to develop a reversible, "on-line" or real-time sensor that can be inserted into the boom of standard spray equipment. Both versions of these smart sensors will be able to collect time and location data via Bluetooth or LTE for precision farming and record keeping. The test(s) we propose developing will directly serve a multibillion dollar market and aid food producers and researchers to better understand crop science. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Our scientists have learned entirely novel and cutting edge skills in biosensor development. How have the results been disseminated to communities of interest?We are in talks with stakeholders ranging from individual farmers to large farm equipment manufacturers and GMO seed producers and herbicide companies. What do you plan to do during the next reporting period to accomplish the goals?Our Phase II proposal has been submitted for review.

Impacts
What was accomplished under these goals? SUMMARY OF PHASE I WORK In our Phase I effort, we determined that a lateral flow test would be unlikely to serve the market needs for a sufficiently sensitive dicamba test, and with the approval of our USDA/NIFA Program Manager, Dr. Steven Thomson, we successfully shifted to a much more powerful electrochemical aptasensing platform. Using this approach, we have demonstrated the at least 3 different sensor configurations that work with our existing dicamba aptamer with the following attributes: Compatibility with customizable OEM square wave voltammetry readers that will be affordable and rugged Sensitivity for dicamba of approximately 3 nM which is 3000-fold better than the sensitivity required for detection of crop-damaging concentrations of dicamba Platform technology that can rapidly be adapted to detection and quantitation of other herbicides and pesticides by simply using different aptamers. Analytes in Phase II will include 2,4-D, glyphosate, glufosinate The Phase 2 SBIR funding will support an ability to develop an unprecedented menu of field-deployable assays for over 50 herbicides and pesticides that can be monitored in a quantitative fashion by farmers, spray applicators, and researchers without the need to send samples to centralized laboratories utilizing expensive mass spectrometry techniques

Publications