Quantum mechanics

Acceptor

Nanoparticle

Photodynamic therapy

Photochemistry

Materials science

Triphenylamine

Small molecule

Biochemistry

Quantum yield

Polymer

Quenching (fluorescence)

Singlet oxygen

Combinatorial chemistry

Physics

Nanotechnology

Organic chemistry

Oxygen

Photothermal therapy

Fluorescence

Condensed matter physics

Conjugated system

Chemistry

Nano-Micro Letters

Simultaneous photothermal therapy (PTT) and photodynamic therapy (PDT) is beneficial for enhanced cancer therapy due to the synergistic effect. Conventional materials developed for synergistic PTT/PDT are generally multicomponent agents that need complicated preparation procedures and be activated by multiple laser sources. The emerging monocomponent diketopyrrolopyrrole (DPP)-based conjugated small molecular agents enable dual PTT/PDT under a single laser irradiation, but suffer from low singlet oxygen quantum yield, which severely restricts the therapeutic efficacy. Herein, we report acceptor-oriented molecular design of a donor–acceptor–donor (D–A–D) conjugated small molecule (IID-ThTPA)-based phototheranostic agent, with isoindigo (IID) as selective acceptor and triphenylamine (TPA) as donor. The strong D–A strength and narrow singlet–triplet energy gap endow IID-ThTPA nanoparticles (IID-ThTPA NPs) high mass extinction coefficient (18.2 L g −1 cm −1 ), competitive photothermal conversion efficiency (35.4%), and a dramatically enhanced singlet oxygen quantum yield (84.0%) comparing with previously reported monocomponent PTT/PDT agents. Such a high PTT/PDT performance of IID-ThTPA NPs achieved superior tumor cooperative eradicating capability in vitro and in vivo.

Molecular Design of Conjugated Small Molecule Nanoparticles for Synergistically Enhanced PTT/PDT