Jie Zhang

Homogeneous oxygen reduction reaction (ORR) studies rely on two predominant electron delivery modes, yet a critical solvent mismatch between electrochemically (aqueous) and chemically (nonaqueous) driven assays invalidates cross-system comparisons of catalytic activity and selectivity for Cu-based molecular catalysts. Herein, we compare ORR catalysis by two pyridinophane-copper(II) complexes, [Cu^tmpa-NH]²⁺ and [Cu^bmpa-NH]²⁺, under matched conditions to evaluate the intrinsic influence of electron delivery modes. Both follow an overall third-order rate law (first-order dependences on [catalyst], [O₂], [acid]) in acetonitrile. However, [Cu^tmpa-NH]²⁺ exhibits 40-fold higher activity and near-exclusive four-electron selectivity (96.42% H₂O), whereas [Cu^bmpa-NH]²⁺ displays mixed two-electron/four-electron behavior (58.22% H₂O₂). Critically, [Cu^tmpa-NH]²⁺ maintains consistent four-electron selectivity and activity across both electron delivery modes, confirming that its intrinsic ORR performance is independent of the electron delivery mode and governed solely by its coordination sphere. This work identifies an easily overlooked issue in chemical ORR assays: decamethylferrocene reacts with in situ formed H₂O₂ in acidic media, interfering with selectivity and kinetic analysis. Notably, a centrosymmetric bis(μ–OH)-bridged dinuclear Cu(II) intermediate generated from the reaction of [Cu^bmpa-NH]⁺ with O₂ has been successfully isolated and structurally characterized. Overall, this work establishes a structure–activity-selectivity relationship for pyridylamine-copper ORR catalysts and provides rational design guidance for their high-performance analogues.

A stable quinoline-linked phenothiazine-based covalent organic framework (QCOF) was constructed. The MXene/QCOF@CNT electrode was then fabricated for flexible supercapacitors. Notably, it achieves 11 Wh kg⁻¹ at 250 W kg⁻¹ and retains 100% of its capacitance even after 5000 cycles, which is attributed to the high stability of the QCOF composite.

Research into vinyl-linked covalent organic frameworks (COFs) has grown significantly in recent years due to various attractive properties.

The performance of chemotherapeutic agents has been largely restrained by the dose-dependent toxic side effects. In this work, cisplatin (CDDP) was endowed with the capability of photoactivated reactive oxygen species (ROS) generation and self-reporting cell uptake via coordination with a small organic molecule MSN. In the resultant MSN-Pt, the Pt-N coordination could obviously enhance the intermolecular charge transfer (ICT) process that allows the integration of fluorescence imaging, photogenerated ROS, and chemotherapeutic performance. The resultant MSN-Pt can recognize between normal and cancer cells and quickly penetrate the cancer cell membrane, self-reporting the cell uptake. Upon light illumination, mitochondria and nuclei were severely damaged. An in vivo mouse model demonstrated that MSN-Pt completely inhibited the tumor growth, exhibiting a higher efficacy compared with that of CDDP. This work provides a facile strategy to develop chemotherapy (CT) drugs for drug-resistant cancers.

Two-photon excited phototherapy has attracted considerable attention due to its advantages such as deeper penetration depth and higher spatial resolution. The lack of a high-performance photosensitizer with large two-photon absorption cross-sections and specific targeting ability makes the efficacy of phototherapy in the treatment of cancer unsatisfactory. Here, a new BODIPY-derived photosensitizer 6DBF₂ is designed with two-photon photosensitization for two-photon excited photodynamic therapy in vivo. 6DBF₂ possesses good two-photon absorption and efficient ¹O₂ generation upon near-infrared laser excitation. Excellent targeting specificities to lipid droplets of 6DBF₂ without any encapsulation or modification at a low working concentration of 0.1 μM is in favor of efficient photodynamic therapy. In vitro cancer cell ablation and in vivo tumor ablation inside mice models upon two-photon irradiation in NIR demonstrate the outstanding therapeutic performance of 6DBF₂ in two-photon excited photodynamic therapy. This work thus discusses a rare example of lipid droplets targeting two-photon excited photodynamic therapy for deep cancer tissue imaging and treatment under near-infrared light irradiation.

Intracellular lipid storage and regulation occur in lipid droplets, which are of great significance to the physiological activities of cells. Herein, a lipid droplet-specific fluorescence probe (lip-YB) with a high quantum yield (QY_lip-YB = 73.28%), excellent photostability, and quickly polarity sensitivity was constructed successfully. Interestingly, lip-YB exhibited remarkable two-photon (TP) characteristics, which first realized real-time monitoring of the lipid droplet multidynamics process, diagnosing nonalcoholic fatty liver disease (NAFLD) and inflammation in living mice via TP fluorescence imaging. It is found that the as-prepared lip-YB provides a new avenue to design lipid droplet-specific imaging probes, clarifies its roles and mechanisms in cell metabolism, and can timely intervene in lipid droplet-related diseases during various physiological and pathological processes.