Intelligent Optical Systems, Inc., in collaboration with Bowling Green State University, proposes to develop a field-rugged, eye-readable indicating spray solution that can immediately detect synthetic opioids over a large area of contamination (i.e., military vehicles, individual protective equipment, clandestine labs, etc.). The proposed chemosensor in a spray solution format will detect multiple opioid derivatives, displaying a distinctive and eye-readable color/fluorescence after coming in contact with a small amount of a particular opioid. This indicating spray solution will overcome the limited detection capability of the current immunoassay that requires sampling from a small area, and suffers from limited shelf life in prolonged and extreme environmental conditions.