Fanggui Ye

Calcium overload therapy represents a highly promising therapeutic strategy and has attracted extensive attention in the field of tumor treatment. Nevertheless, the challenge of achieving high-concentration and precise enrichment of calcium ions inside tumors seriously hinders the clinical translation of this therapy. Moreover, monotherapy fails to deliver superior anti-tumor efficacy. To address such issues, a tumor microenvironment (TME)-triggered calcium ion and hydroxyl radical amplifier with near-infrared absorption (CuMPB@CaCO3@HA) is presented to process calcium overload-synergized multimodal combination therapy. It can bind to the CD44 receptor on the surface of cancer cells, thereby accumulating in tumor tissues, where it is decomposed by the TME to release Ca2+ and copper-doped mesoporous Prussian blue (CuMPB). The released Ca2+ triggers intracellular calcium overload. The released CuMPB has a characteristic absorption peak in the range of 650–900 nm, which enables photoacoustic (PA) imaging and photothermal therapy of the tumor. In addition, Cu2+ in CuMPB undergoes a cascade reaction with highly abundant glutathione and H2O2 in the TME, producing hydroxyl radicals (·OH); additionally, the Fe2+ ion in MPB also undergoes a Fenton reaction with H2O2 to generate ·OH, achieving highly efficient chemodynamic therapy (CDT). Moreover, laser irradiation promotes the generation of ·OH, thereby further enhancing CDT. Both in vitro and in vivo experiments verified that CuMPB@CaCO3@HA enables in situ PA diagnosis of tumors to visualize tumor accumulation and optimize the treatment window and enables PA imaging-guided synergistic calcium overload-chemodynamic-photothermal antitumor therapy based on TME characteristics, thus providing a new strategy for the development of tumor-targeted nanotheranostic agents, highlighting the untapped potential of nanoassembly.

Atherosclerosis (AS) is a risk factor for various cardiovascular diseases (CVD), and early diagnosis and plaque removal are challenges in the management of AS and CVD. To address these challenges, we designed a tungsten‑doped polydopamine nanoparticle (W‐PDA NPs). The near‐infrared (NIR) optical absorption and enzymatic properties of W‐PDA were tuned by adjusting the ratio of W ⁶⁺ to PDA. It was found that the W‐PDA NPs contain a mixture of W ⁶⁺ and W ⁵⁺ , which generated large amounts of free electrons, thus conferring both second near‐infrared (NIR‐II) light absorption capability and superoxide dismutase (SOD)‐ and catalase (CAT)‐like activities. Plaque‐targeting was conferred by appending an anti‐osteopontin antibody via coordination between carboxyl moieties of the antibody with W ⁶⁺ ions on the W‐PDA surface. The NIR‐II light absorption ability can be utilized for photoacoustic diagnosis of AS, while the SOD‐ and CAT‐like activities facilitate the conversion of superoxide into H ₂ O ₂ and subsequently O ₂ , thereby clearing reactive oxygen species and mitigating inflammation, enabling therapy of AS. Thus, the proposed theranostic agent not only can dynamically report the progression of AS but also can effectively treat AS plaques. This strategy holds broad application prospects in the early and accurate diagnosis and treatment of AS.

Conventional fluorescence sensing of o-nitroaniline (o-NA) is frequently limited by unstable exogenous fluorophores and interference-prone "turn-off" readouts. Here, we develop a probe-free, analyte-derived "turn-on" platform based on commercial nano-TiO₂ with programmable charge migration to drive a light-triggered reduction-oxidation cascade. Oxalic acid acts as a hole scavenger to prioritize the electron-driven reduction of o-NA to o-phenylenediamine, while Cu²⁺ dynamically regulates electron flow and markedly enhances peroxidase-like activity to generate reactive oxygen species that efficiently oxidize the intermediate into the strongly emissive 2,3-diaminophenazine. This establishes a fundamentally new "self-luminescence" signal-from-none mechanism in which fluorescence arises uniquely from the target's directional conversion, thereby minimizing batch effects and suppressing false positives from structurally similar nitroaromatics. The platform exhibits a linear detection range of 2.0-40 μM and a detection limit of 0.23 μM, supporting compliance-oriented monitoring in real water matrices.

Unraveling the reversible inhibition mechanisms of nanozymes is critical; however, current research predominantly relies on metal-containing materials, where strong metal-inhibitor interactions often induce irreversible adsorption, complicating the study of reversible inhibition. By comparison, nonmetallic porous materials have emerged as promising candidates for exploring reversible nanozyme inhibition owing their nonmetallic nature, high adsorption capacity, and low mass transfer resistance. Herein, we employed a nonmetallic porous light-responsive nanozyme (denoted TTBT·Cl) and diclofenac sodium (DS) as a model system to systematically investigate reversible inhibition mechanisms. TTBT·Cl not only exhibited high adsorption capacity for oxygen substrates and facilitated mass transfer of both substrate and inhibitor, but also displayed excellent light-responsive oxidase-like activity. Through comprehensive characterization and experimental analyses, the photocatalytic and uncompetitive inhibition mechanisms of the TTBT·Cl nanozyme were clarified. To overcome this inhibitory effect, a selective and sensitive colorimetric platform was developed for DS detection. This study offers a conceptual framework for exploring inhibition mechanisms in other nanozyme systems and has the potential to broaden the application scope of nanozyme-based biosensing.

A hollow GOx@Cu ²⁺ –PA integrated nanozyme was synthesized by utilizing phytic acid (PA) etching and ion exchange methods for the one-step detection of glucose.

3,3'-Dichlorobenzidine (DCB) is an important and widely used intermediate in manufacturing various industrial products; however, DCB is a Group 2B carcinogen and its photodegraded product of benzidine is classified as Group 1 carcinogen. So far, there are few sensing strategies aiming to detect DCB remaining in related industrial products and discharged into the human living environment for assessing its impact on human health in an easy, low-cost, and real-time way. In this work, we found that the recently emerging perovskite nanocrystals (PNCs) with many excellent physiochemical properties could act as both photocatalysts and photochromic materials in the photodegradation of DCB. Under UV irradiation, PNCs catalyze the photodegradation of DCB molecules into benzidine molecules and chloride ions (Cl^-), followed by significant fluorescence wavelength (color) change of PNCs due to ion-exchange between PNCs and the photogenerated Cl^-. Based on the catalytic photodegradation of DCB and photochromism of PNCs, a novel, facile, low-cost, and visualized fluorescent sensor has been developed for the real-time detection of DCB with high sensing selectivity and sensitivity. The novel PNCs-based photochromic fluorescent sensing strategy not only greatly improves the sensing selectivity by innovatively introducing photodegradation and photochromism into the construction of sensing interfaces but also may inspire the applications of the photochromic fluorescent sensors in real-time monitoring of the photodegradation of various environmental pollutants.

Natural enzyme cascades, including the same and different kinds of enzymes, have been widely used in biosensing. However, it is still a challenge for nanozymes, the mimics of natural enzymes, to achieve biosensing with different types of enzyme-like activities based on cascade reactions, such as hydrolase and oxidoreductase. Considering the characteristics of the multienzyme-like activity of some nanozymes, as a proof of concept, this study demonstrates a Cu/Ce-MOF-808 nanozyme as a self-cascade catalyst with hydrolase-like and catechol oxidase-like activities. Taking organophosphorus pesticides as an example, we constructed a self-cascade catalytic reaction for the one-step colorimetric detection of isocarbophos. Specifically, the hydrolase-like activity of Cu/Ce-MOF-808 can hydrolyze isocarbophos to produce colorless isopropyl salicylate, which is further oxidized by the catechol oxidase-like activity of Cu/Ce-MOF-808 and complexed with 4-aminoantipyrine (4-AAP) to produce red quinoneimine under neutral conditions with illumination. Thus, a colorimetric strategy for sensitive isocarbophos analysis is developed, with a linear range of 0.90-400.00 μg·mL^-1 and a detection limit of 0.42 μg·mL^-1. This research presents a new approach to the design and synthesis of nanozymes and has great application potential in the field of nanozyme cascade biosensing.