Photo‐Modulated Reversible Switching of Fluorescence from ZnO Quantum Dots with a Photochromic Diarylethene

Photo-responsive color/fluorescence efficient dual-switching properties of diarylethene modified Eu-doped ZnO@Silane quantum dots

Photo-responsive switches are very promising materials due to their potential applications in many fields. However, photo-controlled color/fluorescence dual-switching with higher modulation efficiency has rarely been reported. Herein, two new optical responsive switches were constructed by Eu-doped ZnO@Silane quantum dots (Eu:ZnO@Silane QDs) and two diarylethenes. The two switches exhibited strong fluorescence intensity and excellent photochromic properties due to the doping of Eu and the diarylethene modification on the surface of the QDs. The switches showed outstanding photo-controlled color/fluorescence dual-switching performance with UV/Vis lights irradiation. Although the structure of the two diarylethenes affected the fatigue resistance of the two switches, their fluorescence modulation efficiency (FME) could reach 100%. Furthermore, the two switches were successfully applied to bioimaging, and provide an alternative way for the design and construction of novel efficient color/fluorescence dual-switching.

Combining Quantum Dots and Photochromic Molecular Switches: Next-Generation Light-Responsive Materials

Quantum dots (QDs), with the unique merits of narrow and tunable photoluminescence (PL) wavelength, high PL quantum yield, have gained significant interest in fields such as display, solar energy conversion, bioimaging, and encrypted quantum communication. On the other hand, photochromic molecular switches (PMS) can undergo reversible interconversion between (at least) two distinct states at the molecular scale upon light irradiation. When combining QDs and PMS, the resulting hybrid systems exhibit synergistic functionalities and light responsiveness, enabling precise and reversible modulation over PL intensity/color, energy/electron transfer, and motion with high temporal and spatial resolution in a non-invasive manner. This perspective explores the recent advancements in the combination method, light-responsive mechanism, and functions of QD-PMS hybrids. The applications of QD-PMS hybrids are also highlighted as light-responsive materials in bioimaging, information processing, sensing, optoelectrical devices, and discuss future challenges, opportunities, and directions for enhancing performance and exploring applications in next-generation light-responsive materials and smart optoelectronic devices.

Construction of a Reversible Solid-state Fluorescence Switching Via Photochromic Diarylethene and Si-ZnO Quantum Dots

Developing fluorescence switching as functional system is highly desirable for potential applications in the fields of light-responsive materials or devices. Attempt to construct fluorescence switching system tend to focus on the high fluorescence modulation efficiency, especially in solid state. Herein, a photo-controlled fluorescence switching system was constructed with photochromic diarylethene and trimethoxysilane modified zinc oxide quantum dots (Si-ZnO QDs) successfully. It was verified by the measurement of modulation efficiency, fatigue resistance as well as theoretical calculation. Upon irradiation with UV/Vis lights, the system exhibited excellent photochromic property and photo-controlled fluorescence switching performance. Furthermore, the excellent fluorescence switching characters could also be realized in solid state and the fluorescence modulation efficiency was determined to be 87.4%. The results will provide new strategies to the construction of reversible solid-state photo-controlled fluorescence switching for the application in the fields of optical data storage and security labels.

A photo-controlled fluorescent switching based on carbon dots and photochromic diarylethene for bioimaging

Carbon dots (CDs) as luminescent zero-dimensional carbon nanomaterials have good aqueous dissolution, photostability, high quantum yield, and tunability of emission color. It has great application potential in many fields, including bioimaging, labeling of biological species, drug delivery, and sensing in biomedical. However, controlling the fluorescence emission of carbon dots remains a formidable challenge. Herein, we designed and exploited a photo-controlled fluorescent switching based on photochromic diarylethene (DT) and CDs for bioimaging. It could be modulated reversibly between "ON" and "OFF" under UV/vis light exposure. The fluorescent modulation efficiency was as high as 95.3%. The fluorescent switching could be used to the bioimaging in HeLa cells with low cell toxicity. Therefore, this fluorescent switching could be a promising candidate in many potential application areas, especially in bioimaging.

Construction of a photo-controlled fluorescent switching with diarylethene modified carbon dots

Photo-controlled fluorescent switching is of great utility in fluorescence sensors, reversible data storage, and logic circuit, based on their modifiable emission intensity and spectra. In this work, a novel photo-controlled reversible fluorescent switching system was constructed based on photochromic diarylethene (DT) molecular modified fluorescent carbon dots (CDs). The fluorescent CDs acted as fluorescent donors and the photochromic diarylethene molecular functioned as acceptors in this fluorescent switching system. The fluorescence modulation efficiency of the fluorescent switching was determined to be 97.1%. The result was attributable to Förster resonance energy transfer between the CDs and the diarylethene molecular. The fluorescent switching could undergo 20 cycles without significant decay.