Conjugate Addition/Cyclization Sequence Enables Selective and Simultaneous Fluorescence Detection of Cysteine and Homocysteine

Similar but different: A benzothiazole derivative can be used to detect cysteine (Cys) and homocysteine (Hcy) simultaneously in neutral media. The method involves thioether formation followed by cyclization to release 2-(2′-hydroxy-3′-methoxyphenyl)benzothiazole (HMBT) and a lactam. The differences in ring-formation kinetics allow spectral or kinetic modes to be used to identify Cys and Hcy. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.