In situ formation of phosphorescent molecular gold(I) cluster in a macroporous polymer film to achieve colorimetric cyanide sensing.

A highly phosphorescent molecular Au(I) cluster capable of rapid, sensitive, and selective detection of cyanide has been successfully fabricated. The origin of the outstanding sensing performance of the molecular Au(I) cluster toward cyanide is justified by X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) analyses. The response mechanism employed with the molecular Au(I) cluster and the cost-effectiveness in cyanide detection affords several key sensor features, making this molecular Au(I) cluster-based sensor unique compared to other cyanide sensing schemes. Importantly, by exploring the phosphorescent properties of the molecular Au(I) cluster in solid state, we demonstrate the first example of the molecular gold(I) cluster-based macroporous sensing film for colorimetric detection of cyanide in complex samples, including red wine, coffee, juice, and soil. Remarkably, the as-prepared sensing film inherits the sensing ability of the molecular Au(I) cluster, and offers a high mechanical flexibility and novel opportunities for real-time monitoring cyanide release in cassava manufacturing.