selective detection of peroxycarboxylic acid by thiocarbonyl compounds in aqueous solution

Abstract In this study, two fluorescent probes for efficient detection of peroxycarboxylic acid were designed and synthesized. An OFF–ON probe THPY was composed of Pyonin B skeleton and a thioketone group, while the ratiometric probe THCA was based on 4-methylcoumarin skeleton with a thioester group. Both of them showed good selectivity and sensitivity toward peroxycarboxylic acid over other analytes. Especially, detection systems got good operation in aqueous solution containing common ions. The detection mechanism was achieved via thiocarbonyl oxidative desulfurization, which eliminated the inter system crossing (ISC) effect caused by thiocarbonyl structure. The detection limits of THPY were calculated to be 534 nM for peracetic acid (PAA) and 73.6 nM for m-chloroperoxybenzoic acid (mCPBA), and those of THCA were 216 nM for PAA and 230 nM for mCPBA, respectively. The satisfactory results were obtained in the test of actual samples and test strips. All in all, the research produced an effective and stable detection system for peroxycarboxylic acid, and it also proved the possibility of designing probe by controlling ISC effect.