A novel luminol-related hydroxyphenyl benzothiazole analogue chemiluminescence probe with ultrahigh sensitivity for bloodstain detection†

Based on the chemical structure and luminescence mechanism of luminol, the synthesis of luminol analogues has been widely studied. However, luminol and its derived reagents are still suffering from some drawbacks, such as short luminescence time and weak intensity. Herein, we designed and synthesized a novel hydroxyphenyl benzothiazole-based phthalhydrazide derivative DAH-AMPH, which has a hydroxyphenyl benzothiazole structure as a strong fluorescent site and a cyclic phthalhydrazide structure as a chemiluminescence (CL) emitting site. DAH-AMPH exhibited excellent CL properties in the DAH-AMPH/UHP/hemin CL system for hemin detection with a wide linear range of 0.1 nM to 20.0 nM and low LOD of 3 pM. It exhibited good selectivity in bloodstain imaging on different substrate materials. The DAH-AMPH/UHP/hemin CL system represents a powerful tool for trace detection of bloodstains. Moreover, as a new CL substrate for HRP, DAH-AMPH showed high sensitivity (0.8 pg mL⁻¹ of LOD) in the DAH-AMPH/UHP/SPTZ/MORP/HRP CL system indicating bright prospects for the use of DAH-AMPH in heme-containing peroxidase detection.