Development of a highly selective colorimetric pyrophosphate probe based on a metal complex and gold nanoparticles: change in selectivity induced by metal ion tuning of the metal complex

In this study, we developed a colorimetric sensing system for pyrophosphate (PPi) with a probe composed of phosphate functionalized-gold nanoparticles as the reporter unit and [Cu3(1,3,5-tris[bis(pyridine-2-ylmethyl)aminomethyl]-2,4,6-triethylbenzene)]6+ (2) as the receptor unit. The proposed probe allows easy detection of PPi with the naked eye, and selectively recognizes PPi with a detection limit of 320nM. Unlike previous AuNP based-PPi sensing systems, this probe exhibits high selectivity for PPi over various other phosphate derivatives including adenosine triphosphate (ATP) and adenosine diphosphate (ADP).