Cobalt dual-atom clusters with strong chemiluminescent response for analyzing pathogenic bacteria by using cell wall bind domain as recognizer

As new type of catalysts, dual or multiple atomic clusters have displayed extremely high atom utilization rate and superior catalytic activity. In the present work, a metal binuclear atom pair with unique cobalt coordination environment of Co2-O8 were prepared on the supports of MOFs MIL-53(Al), and named as Co dual-atom clusters (CoDACs). Fascinatingly, CoDACs with desirable water dispersibility display very high catalytic efficiency for redox-based chemiluminescent (CL) reaction by generating abundant reactive oxygen species. The catalysts boosted the CL signal of luminol-H2O2 system for 1192 times as their concentration were 1.0 μg mL-1, thus can be applied as superior CL probes for tracing biorecognition events. To verify their application potential, CoDACs were used to establish a CL method for analyzing methicillin-resistant Staphylococcus aureus (MRSA) strains by adopting cell wall bind domain of bacteriophage P108 as a recognizer. The method displays a dynamic range of 6.1 × 102 - 6.1 × 107 CFU mL-1 and a detection limit of 220 CFU mL-1. The results for analysis of MRSA in biological, drug and food samples manifest their reliability for real application. To our best knowledge, it is the first study focusing on DACs as efficient catalysts for CL reaction.