Luciferin Synthesis and Pesticide Detection by Luminescence Enzymatic Cascades.

D-Luciferin (D-LH 2 ), a substrate of firefly luciferase (Fluc), is important for a wide range of bioluminescence applications. This work reports a new and green method using enzymatic reactions (HELP, HadA Enzyme for Luciferin Preparation) to convert 19 phenolic derivatives to 8 D-LH 2 analogues with ≈51 % yield. The method can synthesize the novel 5'-methyl-D-LH 2 and 4',5'-dimethyl-D-LH 2 , which have never been synthesized or found in nature. 5'-Methyl-D-LH 2 emits brighter and longer wavelength light than the D-LH 2 . Using HELP, we further developed LUMOS (Luminescence Measurement of Organophosphate and Derivatives) technology for in situ detection of organophosphate pesticides (OPs) including parathion, methyl parathion, EPN, profenofos, and fenitrothion by coupling the reactions of OPs hydrolase and Fluc. The LUMOS technology can detect these OPs at parts per trillion (ppt) levels. The method can directly detect OPs in food and biological samples without requiring sample pretreatment.