Hybrids Based on Graphene Oxide and Porphyrin as Tools for Detection and Stabilization of DNA G‑Quadruplexes

Telomerase inhibition has been an important strategy in cancer therapies, but for which effective drugs are still required. Here, noncovalent hybrid nanoplatforms containing the tetracationic 5,10,15,20-tetrakis­(1-methyl-pyridinium-4-yl)­porphyrin (TMPyP) and graphene oxide (GO) were prepared for promoting telomerase inhibition through the selective detection and stabilization of DNA guanine-quadruplex (G-Q) structures. Upon binding TMPyP to the GO sheets, the typical absorption bands of porphyrin have been red-shifted and the fluorescence emission was quenched. Raman mapping was used for the first time to provide new insights into the role of the electrostatic and π–π stacking interactions in the formation of such hybrids. The selective recovery of fluorescence observed during the titration of TMPyP@GO with G-Q, resembles a selective “turn-off–on” fluorescence sensor for the detection of G-Q, paving the way for a new class of antitumor drugs.