Bioresponsive near-infrared fluorescent probes have the attractive performance feature that strong fluorescence signal is observed only at a specific bioresponsive region of space or point in time, and the background signal beyond that region is very low. The potential benefit of this bioresponsive approach is driving ongoing research efforts to develop new classes of activatable near-infrared fluorescent probes. Here, we report a new probe design that is comprised of a cyanine heptamethine (Cy7) fluorophore with a C4’-benzyl ester group that has an appended Trigger Group. Chemical activation of the Trigger Group by enzyme catalyzed reaction induces self-immolative cleavage (1,6-elimination) to produce the corresponding C4’-carboxylic acid with greatly enhanced fluorescence. We validate this new probe design by developing two prototype probes that indicate cell hypoxia. In one case, the chemical activation reaction is reduction of a nitro group by nitroreductase enzyme and in the other case it is enzymatic reduction of an azo group. Both probes permit near-infrared microscopic imaging of cell hypoxia with “turn on” fluorescence. I exceedingly wish to talk more and present on the importance of our research, synthetic design of our Cy7 probes, enzyme solution studies and epifluorescence results at the ACS Spring 2021 through a poster. I believe ACS Spring 2021 is an incredible opportunity for future scientists like me to share our work, comprehend other interesting research fields, interact with fellow scientists, and avail a broader perspective of the scientific field.

Fluorogenic near-infrared heptamethine cyanine probes for microscopic imaging of tumor hypoxia

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.