Pyrophosphate (PPi) is released from gene replication and expression catalyzed by DNA polymerases and aminoacyl-tRNA synthetases, respectively. These enzymatic activities are usually linked to common genetic diseases, and therefore their monitoring is now indispensable technique in therapeutic and diagnostic research. For decades, phenoxo-bridged binuclear Zn2+–dipicolylamine complex (ZnDPA) has been extensively utilized as a ligand for the fluorescent detection of PPi. However, its low selectivity for PPi in the presence of excess nucleoside triphosphates (NTPs) still remains a major obstacle to the real-time monitoring of related enzymatic reactions involving the release of PPi, because usually a small amount of PPi is released in the presence of a large amount of NTPs during the enzymatic reactions. To address this issue, we developed a new PPi detection method that combines the well-known surface characteristics of graphene oxide (GO) and the selective recognition ability of the ZnDPA based probe (1). Complex GO-1 formed by electrostatic interactions between negatively charged GO and positively charged probe 1 provides an ideal platform for the electrostatics-driven PPi detection method. A dramatic change in the fluorescence intensity of 1 occurred when PPi was added to the electrostatically attractive patch (GO-1), which originates from charge inversion in 1-PPi upon binding the highly complementary target (PPi), concomitantly resulting in Columbic repulsion between GO and 1-PPi. GO-1 conjugate system exhibited excellent selectivity towards PPi even in the presence of excess ATP. Consequently, GO-1 was successfully applied for polymerase chain reaction monitoring that requires highly selective and sensitive detection of PPi.

Graphene oxide-probe conjugate for the selective detection of pyrophosphate

253rd National Meeting (2017)

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