Search

[Display omitted] • Low-power non-coherent light-triggered two-photon absorption process with long-lived transition state: consecutive photo-induced electron transfer and triplet triplet annihilation upconversion. • Supramolecular approaches to extending the lifetime of radical anion or triplet state of dye molecules. • Applications in photoredox catalysis, 3D printing, cancer treatment and bioimaging. • The challenges and future directions are proposed. Materials with multi-photon absorption (MPA) feature, are highly desirable for applications such as deep-seated tumor treatment, high spatiotemporal resolution bioimaging, sophisticated micro-nano fabrication, optical data storage, frequency-upconverting laser, and optical limiting. The classical two-photon absorption (TPA) process relies on an extremely short-lived virtue state, leading to the requirement of an ultrahigh power density of femtosecond pulsed laser. To break this application barrier, the key solution is to extending the lifetime of the transition state in TPA. Recently, the operation of TPA with low-power non-coherent excitation (LPNC-TPA) was achieved by leveraging the mono-reduced species (such as radical anion) and the triplet excited state of dye molecules as the transition state with a relatively long lifetime. In this review, the mechanism of these LPNC-TPA processes will first be introduced, followed by the approaches to extend the lifetime of the mono-reduced species and the triplet state. Then, considering its ability to tune the aggregation mode of dye molecules, the metal–organic framework (MOF) will be emphasized as an efficient tool to operate efficient LPNC-TPA in the solid state. The merits and features of LPNC-TPA materials will be revealed through their emerging applications in photoredox catalysis, photopolymerization, 3D printing, in vivo cancer treatment, bioimaging, and biosensing. Finally, the future directions and challenges of LPNC-TPA are proposed, along with the possible solutions. [ABSTRACT FROM AUTHOR]

Organic self‐assembled co‐crystals have garnered considerable attention due to their facile synthesis and intriguing properties, but supramolecular interactions restrict their stability in aqueous solution, which is especially important for biological applications. Herein, we report on the first biological application of aqueous dispersible self‐assembled organic co‐crystals via the construction of metal–organic framework (MOF) ‐stabilized co‐crystals. In particular, we built an electron‐deficient MOF with naphthalene diimide (NDI) as the ligand and biocompatible Ca2+ as the metal nodes. An electron donor molecule, pyrene, was encapsulated to form the host–guest MOF self‐assembled co‐crystal. We observed that such MOF structure leads to uniquely high‐density ordered arrangement and the close intermolecular distance (3.47 Å) of the charge transfer pairs. Hence, the concomitant superior charge transfer interaction between pyrene/NDI can be attained and the resultant photothermal conversion efficiency of Py@Ca‐NDI in aqueous solution can thus reach up to 41.8 %, which, to the best of our knowledge, is the highest value among the reported organic co‐crystal materials; it is also much higher than that of the FDA approved photothermal agent ICG as well as most of the reported MOFs. Based on this realization, as a proof of concept, we demonstrated that such a self‐assembled organic co‐crystal platform can be used in biological applications that are exemplified via highly effective long wavelength light photothermal therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] Phototherapy is a noninvasive cancer treatment that relies on the interaction between light and photoactive agents. These photoactive agents are typically organic dyes, but their hydrophobic nature and self-aggregation tendency in biological media greatly restricts the development of highly effective phototherapeutic systems. In the past decade, functional dye-doped metal–organic framework (MOF)-based phototherapy has attracted enormous interest because organic dyes can be encapsulated and isolated within the MOF structure to show superior treatment efficacy. In addition to incorporating the reported phototherapeutic dyes into MOF as the ligand or the guest in the pores, the construction of an MOF-based phototherapy agent can also be extended to these dye units that are previously inactive for phototherapy. Thus, this review focuses on the emerging development of phototherapeutic MOFs that exhibited better performance than the involving dye units due to the controlled dye aggregation within the MOF. The related mechanisms and some emerging future directions of dye-doped MOF-based phototherapy are also discussed and summarized. [ABSTRACT FROM AUTHOR]

Keywords: charge-transfer interaction; metal-organic framework; organic co-crystal; photothermal therapy; self-assembly EN charge-transfer interaction metal-organic framework organic co-crystal photothermal therapy self-assembly 23465 23465 1 10/20/21 20211025 NES 211025 B Lanterns on water b resemble aqueous dispersible metal-organic framework (MOF) structures composed of an alternating arrangement of donor and acceptor molecules. GLO:44U/25oct21:anie202111740-toc-0001.jpg PHOTO (COLOR): . gl GLO:44U/25oct21:anie202111740-toc-0001.jpg PHOTO (COLOR): . gl B Lanterns on water b resemble aqueous dispersible metal-organic framework (MOF) structures composed of an alternating arrangement of donor and acceptor molecules. Charge-transfer interaction, metal-organic framework, organic co-crystal, photothermal therapy, self-assembly. [Extracted from the article]

Charge-transfer interaction, metal-organic framework, organic co-crystal, photothermal therapy, self-assembly Keywords: charge-transfer interaction; metal-organic framework; organic co-crystal; photothermal therapy; self-assembly EN charge-transfer interaction metal-organic framework organic co-crystal photothermal therapy self-assembly 23657 23657 1 10/20/21 20211025 NES 211025 B Lampions auf dem Wasser b repräsentieren in Wasser dispergierbare metallorganische Gerüststrukturen (MOFs), die aus einer alternierenden Anordnung von Donor- und Akzeptormolekülen bestehen. Titelbild: Self-Assembled Metal-Organic Framework Stabilized Organic Cocrystals for Biological Phototherapy (Angew. [Extracted from the article]