Kinetically Orthogonal Probe for Simultaneous Measurement of H 2 S and Nitroreductase: A Refined Method to Predict the Invasiveness of Tumor Cells.

The concentrations of nitroreductase and H 2 S have been widely used to predict the invasiveness of tumors. However, the above two substrates always interfere with the measurement of each other as both substrates react with the typical nitroaromatic probe with the same process. Moreover, the above interferences may lead to the misjudgment of the tumor invasiveness. We used a strategy combining kinetical distinguishing and signal amplification to construct a kinetically orthogonal probe labeled KOP. The above strategy expanded the gap between the reactivity of KOP to H 2 S and nitroreductase with an acceptable reactivity and could determine the concentration of coexisting nitroreductase and H 2 S on a kinetic curve with a breakpoint. KOP could also indicate the correct invasiveness tendency in the cellular model with a complex H 2 S generation pathway, while the traditional kinetically nonorthogonal probe could not indicate invasiveness correctly.