Exploiting negative photochromism to harness a four-photon-like fluorescence response with two-photon excitation.

ABSTRACT: Combining nonlinear optical processes and photoswitching transcends the limitations of conventional and even standalone super-resolution imaging. While photoswitching enables resolution improvement, it is typically constrained by limited imaging depth, potential phototoxicity and the low number of inherently fluorescent photoswitches. Nonlinear excitation, such as two-photon absorption, addresses some of these challenges. Here, we present a molecular design strategy that unites the molecular control of T-type negative photoswitches (PS) and two-photon absorption. In these designs, two-photon absorbing push-pull fluorophores that function as FRET-donors are linked to T-type negative PS FRET-acceptors, e.g., donor-acceptor Stenhouse adducts (DASA) or 1,1'-binaphthyl-bridged imidazole dimers.

SUBMITTER: Benitez-Martin C 

PROVIDER: S-EPMC12678773 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature