DESCRIPTION (provided by applicant): The objective of this proposal is to assess the feasibility of a fully integrated device for the rapid and early diagnosis of cyanide poisoning in whole blood using the spectral shift of the vitamin B12 precursor cobinamide upon binding with cyanide as an indicator. Cyanide is an extremely potent and rapid acting poison with as little as 50 mg fatal to humans. Currently there are no portable rapid tests for the detection of cyanide in whole blood available. The primary goal of this proposal is to demonstrate feasibility of the cobinamide-cyanide chemistry in a rapid test using a whole blood sample from a finger-stick. The total assay time from the sample collection to a valid result will be less than 5 minutes. The innovation in this proposal is to incorporate the cobinamide chemistry with blood separation technology, fluid path designs, and a detection area, all integrated in a compact, disposable device which can be interpreted with a handheld visualization system. Feasibility work of this novel rapid assay for detecting blood cyanide through cobinamide will initially focus on several technical approaches for the device design. Parallel paths to pursue a wet chemistry design, a design where the reagents are dried in the device, and a combination thereof will be considered, compared and evaluated. In all of the proposed methods the whole blood sample will be added to the device, followed by an integrated whole blood processing step to yield a plasma sample. Either prior to or immediately after the whole blood separation and lysis, the sample will be mixed with the on-board reagent, dried or wet, and possibly buffers. The processed sample-reagent mixture then moves through the device through various fluid paths to a detection area. To allow for sufficient mixing time between the sample and the reagents, different fluid paths, mixing chambers, polymeric time-gates, and dissolvable films will be evaluated with the goal of maximizing the interaction time. The spectral shift of cobinamide upon binding of cyanide to cobinamide will be measured in the detection area using a handheld or small, portable reader instrument. Upon successful completion of this Phase 1 project we intend to further develop our concept/prototype assay, complete the device design and integrate the finished test with a reader instrument through a Phase 2 proposal. Specific aims for a Phase 2 of this project include the validation of the cobinamide-based device for measuring cyanide in blood. Results will be compared to two established methods for measuring cyanide in biological samples. The sensitivity, specificity, accuracy, precision, and reproducibility of the devices will be determined. Additional studies will be designed to obtain regulatory approval and subsequently we will commercialize the test. If successful, this test will provide the medical community and first responders with a fast, reliable and economic alternative to determine cyanide poisoning.
PUBLIC HEALTH RELEVANCE: Cyanide poisoning has been recognized as a threat from smoke inhalation and potentially through weapons of mass destruction, but there are currently no methods available to rapidly detect cyanide in blood from at-risk patients. The objective of the proposed work is to assess the feasibility of a fully integrated method for the rapid and early detection and diagnosis of cyanide poisoning in whole blood using the spectral shift of the vitamin B12 precursor cobinamide upon binding with cyanide as an indicator. Successful accomplishment of the goals of this project will be the basis for the development of a test to detect and measure cyanide blood poisoning which will allow healthcare providers to treat patients quickly and effectively.