The project addresses an important problem that has a direct impact on human and animal health. Mold produced aflatoxins are carcinogenic and represent a direct threat to human health. The product is a nano- crystalline tin oxide sensor. This sensor employs interdigitated electrodes for measurement of the change of the bulk resistance of the tin oxide semiconductor film as it encounters organic vapors emanating from the mold as it produces the aflatoxin. The approach is innovative because it addresses the main obstacles to fabrication of an accurate, fully functional, cost-effective sensor. The basic tin oxide sensory material will be nano-structured in composition and therefore will provide the necessary step function increase in the number of active sites required for exceptional performance. The long term objective is the protection of United States food and feed grains from contamination by aflatoxins, potent hepatocarcinogens produced by Aspergillus flavus. A number of A. flavus strains (toxigenic and atoxigenic ) will be employed in this Phase I study. Microbiological growth assays will determine the volatiles produced by each of the test fungi on corn seeds. Aflatoxins will be identified and quantified by High Performance Liquid Chromaotography (HPLC). Gas chromatography will be used to identify volatiles present. The unique and prevalent volatiles associated with the toxigenic strains will be used as test markers in the Sensor Development Corporation test system. Successful completion of this project will demonstrate the feasibility of distinguishing a particular target gas from all other gases in a mixture, particularly for those gases associated with aflatoxin production in combination with other microbial emanations and potential interferants.
The specific aims of this work are: 1) Identify unique volatile compound(s) associated with aflatoxin production by Aspergillus flavus growing on corn; and 2) Identify sensor operating conditions and catalyst(s) which will allow specific airborne volatiles of Aim 1 to be selectively detected and quantified in atmospheres which also contain a mixture of non-specific volatiles and potential interferants. Phase II will involve selecting sensors for installation in a test prototype device. These sensors will be installed in the device and the prototype modified to support testing activity. The commercial implication of this work is to bring to the Agricultural industry a much needed new product based on a disruptive technology offering a new way to rapidly detect mycotoxins in stored grains in real-time. This will provide access to a multi billion dollar US market in which key trends are favorable i.e. US and the world are demanding higher quality less toxins - because of an increased public consciousness of safety issues in human and pet foods.
The prevalence and level of human exposure to aflatoxin on a global scale has been reviewed, and the resulting conclusion is that approximately 4.5 billion persons in the world are chronically exposed to largely uncontrolled amounts of the toxin. The aflatoxin exposure and the toxic affects on immunity and nutrition combine to negatively affect health factors (including HIV infection) that account for greater than 40% of the burden of diseases in developing countries where a short lifespan is prevalent. Children exposed to aflatoxin may become stunted, underweight, and more susceptible to infectious diseases in childhood and later life. ? ? ?
