Colorimetric logic design for rapid and precise discrimination of nitrate-based improvised explosives

Rapid and precise sensory arrays could help mitigate against terrorist attacks with improvised explosives. However, the complexity of data processing methods is one of the greatest barriers to the future development of sensory arrays. Here, we present a colorimetric logic design that makes full use of a YES/NO logic gate for rapid discrimination and a colorimetric decoder for further precise judgment. The identification ability of this logic design for the most popular improvised explosives (i.e., nitrate-based improvised explosives), including black powder (BP), ammonium nitrate (AN), urea nitrate (UN), and their related constituents, is verified by integrating different colorimetric hydrogel units into a sensory array. Although the resulting outcome validates this methodology effectively, it remains at proof-of-concept. That said, we believe that its application could also be extended to other fields, such as drug detection, environmental pollution, and diagnostic devices.