Computational Design of Two-Photon Fluorescent Probes for Intracellular Free Zinc Ions

Abstract

Two-photon fluorescence probes used in two-photon fluorescence microscopy (TPM) can achieve intact tissue imaging without destruction. Therefore, for a long time, TPM has been an important tool in biology and medicine. In this background via a quantum chemical method, a series of zinc ion probe molecules using N,N-di(2-picolyl)ethylenediamine (DPEN) as the recognition group were studied, which are based on the photoinduced electron transfer (PET) mechanism. The fact that the one-photon absorption peak is almost unchanged and the fluorescence emission intensity increased significantly upon coordination with a zinc ion reveals that these probes can be PET fluorescent bioimaging reagents. And it is predicted that when the chemically modified probe molecule is incorporated with Zn(2+), the two-photon absorption (TPA) cross-section (δmax) will greatly increase and the TPA peak will be in the near-infrared region. The molecules after changing the fluorophore become more suitable for probing Zn(2+) in vivo, and a modification at the end of the fluorophore can fine-tune the fluorescence and TPA properties. The detailed investigations will provide a theoretical basis for synthesizing new zinc-ion-responsive two-photon fluorescent probes.

Thiol-Activated Triplet–Triplet Annihilation Upconversion: Study of the Different Quenching Effect of Electron Acceptor on the Singlet and Triplet Excited States of Bodipy

“…DFT calculations were carried out for rationalization of the photophysical properties of the compounds. − First, the spin density surfaces of C-1 and C-2 were calculated (see the Supporting Information, Figure S43). , The T 1 triplet excited states of both C-1 and C-2 are confined on the diiodo-Bodipy moieties, which are in agreement with the nanosecond transient absorption spectra of the compounds. For 2 , the spin density surface is confined on the Bodipy moiety, not the DNBS moiety.…”

MOF/COF hybrids as next generation materials for energy and biomedical applications

“…1 shows the distribution of the main application areas of MOF/COF hybrids and the timeline of the pioneering works on the utilization of MOF/COF hybrids. Recent comprehensive reviews show that the number of works on these composite materials is rapidly increasing, 2,3,13,[23][24][25][26][29][30][31][32][33] and MOF/COF hybrids have already been utilized in various applications such as for energy storage, 2 photocatalysis, 26 or biosensing. 33 In this highlight, our aim is to provide a concise and critical overview of the advancements in the applications of MOF/ COF hybrids with a special emphasis on the use of computational tools to uncover their potentials.…”

A Dicyanocarbazolylstilbene‐Derived Two‐Photon Fluorescence Probe for Lipid Raft with a Large Two‐Photon Action Cross Section

“…Based on the molecular simulation calculation, Ai-Min Ren had theoretically proved that, as a fluorophore, DCS was able to lead to a significant increase in δΦ. [20] On this basis, we modified the molecular structure of the probe by introducing a lipophilic long carbon chain (C 8 H 17 ), which is similar to that of eight carbon atoms in cholesterol with the purpose of augmenting the compatibility of the probe with the cytoplasmic membrane (biliphytic molecular layer), and improving the matching between probe molecule and lipid raft. In addition, the benzene ring was replaced by the fused-ring carbazole moiety to enhance the rigidity of molecular plane: one was to improve the two-photon absorption cross-section (δ TPA ) of the probe molecule to emit stronger fluorescence, which greatly heighten the sensitivity; the other was to reduce the effect of water solution polarity (or cell fluid polarity) upon the fluorescence of the probe, [19,21] and to focus the probe on the response to viscosity, namely lipid raft, so as to enhance the accuracy of the detection; another was to boost the affinity and efficacy of the probe with lipid raft rooting from the comparability between the rigidity of molecular plane for the probe and the rigid lipid raft with rich glycosphingolipids and cholesterol.…”