There were more than 22,000 reported chemical spills and related incidents on our rails and highways in 2021, resulting in 2,800 injuries or deaths and $6.8 billion in economic loss. For the nearly 2 million U.S. police and firefighters – the first responders to such events – the ability for rapid, mobile, and inexpensive detection of toxic gases or vapors is extremely limited. Current technology to detect toxic gases are too expensive, too insensitive, too slow, too cumbersome, or not sufficiently specific. Our Optoelectronic Nose will protect first responders and save lives from chemical spills and industrial fires by rapidly detecting toxic chemicals.