Dual-Channel Fluorescent Probe for the Simultaneous Monitoring of Peroxynitrite and Adenosine-5′-triphosphate in Cellular Applications

[Image: see text] Changes in adenosine triphosphate (ATP) and peroxynitrite (ONOO(–)) concentrations have been correlated in a number of diseases including ischemia-reperfusion injury and drug-induced liver injury. Herein, we report the development of a fluorescent probe ATP-LW, which enables the simultaneous detection of ONOO(–) and ATP. ONOO(–) selectively oxidizes the boronate pinacol ester of ATP-LW to afford the fluorescent 4-hydroxy-1,8-naphthalimide product NA-OH (λ(ex) = 450 nm, λ(em) = 562 nm or λ(ex) = 488 nm, λ(em) = 568 nm). In contrast, the binding of ATP to ATP-LW induces the spirolactam ring opening of rhodamine to afford a highly emissive product (λ(ex) = 520 nm, λ(em) = 587 nm). Due to the differences in emission between the ONOO(–) and ATP products, ATP-LW allows ONOO(–) levels to be monitored in the green channel (λ(ex) = 488 nm, λ(em) = 500–575 nm) and ATP concentrations in the red channel (λ(ex) = 514 nm, λ(em) = 575–650 nm). The use of ATP-LW as a combined ONOO(–) and ATP probe was demonstrated using hepatocytes (HL-7702 cells) in cellular imaging experiments. Treatment of HL-7702 cells with oligomycin A (an inhibitor of ATP synthase) resulted in a reduction of signal intensity in the red channel and an increase in that of the green channel as expected for a reduction in ATP concentrations. Similar fluorescence changes were seen in the presence of SIN-1 (an exogenous ONOO(–) donor).