Sensitive and accurate monitoring of urinary albumin and point-of-care testing using a fluorescent probe with anti-interference capacity against exogenous drugs.

Fluorescent probes have been reported for monitoring urinary albumin (u-ALB) to enable early diagnosis of kidney diseases and facilitate regular point-of-care testing (POCT) for chronic kidney disease (CKD) patients. However, the albumin can bind hydrophobic drugs through host-guest interactions, which may result in decreased accuracy of probes at regular drug sites and hamper POCT of albuminuria since CKD patients often need to take medications routinely. Herein, we reported a novel fluorescent probe (NC-2) by molecular engineering of a reported AIEgen (NC-1). The introduction of a non-conjugated ring moiety to the molecular rotor granted the NC-2 enhanced sensitivity with a limit of detection in urine of 8.7 mg/L, which is below l the threshold of microalbuminuria (30 mg/L). Moreover, the NC-2 was found to preferentially bind to the FA1 site of ALB, conferring it with excellent anti-interference capacities against exogenous drug molecules and metabolites. Simulation experiments using lab-spiked urine samples containing common drugs taken by CKD patients demonstrated that the probe could provide satisfied detecting accuracy (80-90 %). Furthermore, a paper-based device was constructed and achieved on-site detection of u-ALB in qualitative and semi-quantitative manners. Findings in this work were of great significance to the development of fluorescent probes for accurate detection of ALB in complex urine samples and the further achievement of fluorescence-based POCT for CKD.

Effect of Reaction Conditions on Energy Yield of Pyrolysis Gas from Apple Tree Branches.

Although the annual branches of apple trees are substantial, most of them are discarded or incinerated, resulting in a significant waste of resources and environmental pollution concerns. Therefore, it has become necessary and urgent to recycle these branches. Compared with crop straw, apple tree pruning branches exhibit a relatively elevated lignin content, which makes them an optimal feedstock for generating high-quality pyrolysis gases. Energy yield can comprehensively measure the gas production and heat value of the pyrolysis gas. Herein, the effect of reaction conditions on the energy yield of the pyrolysis gas is systematically investigated. The single-factor experimental results show that the optimal conditions are 750 °C reaction temperature, 2 °C/min heating rate, and 120 min holding time. The central composite design test of the response surface establishes that temperature has the most impact, followed by heating rate and holding time. In addition, a regression model is constructed to predict the energy yield of the pyrolysis gas. The analysis of interactions between factors indicates that factors within the lower temperature zones, higher heating rate, and shorter holding time have a more significant influence on the energy yield. These findings provide crucial guidance for the efficient production of pyrolysis gas from apple tree branches.

Instant in situ highlighting of latent fingerprints by a green fluorescent probe based on aggregation-induced emission.

Fluorescence sensing of latent fingerprints (LFPs) has gained extensive attention due to its high sensitivity, non-destructive testing, low biotoxicity, ease of operation, and the potential for in situ visualization. However, the realization of in situ visualization of LFPs especially with green emission and rapid speed is still a challenge. Herein, we synthesized an amphibious green-emission AIE-gen TPE-NI-AOH (PLQY = 62%) for instant in situ LFP detecting, which integrates the excellent fluorescence properties of naphthalimide (NI) with a hydrophilic head and the AIE character as well as the donating property of tetraphenylethene (TPE). TPE-NI-AOH in ethanol/water binary solvent was used as an environmentally friendly LFP developer and achieved in situ green-fluorescence visualization of LFPs. The fluorescence signal achieves its 60% saturated intensity in 0.37 s and nearly 100% in 2.50 s, which is an instant process for the naked eye. Moreover, level 3 details and super-resolution images of LFPs could be observed clearly. Besides, the TPE-NI-AOH developer could be stored for at least 6 months, suitable for long-term storage. This instant in situ highlighting method does not require post-processing operations, providing a more convenient, rapid, and efficient detection method of LFPs. This work would inspire the further advancement of fluorescent sensors for fingerprint imaging.

Fluorescent hyaluronic acid nanoprodrug: A tumor-activated autophagy inhibitor for synergistic cancer therapy.

Autophagy is a process that eliminates damaged cells and malfunctioning organelles via lysosomes, which is closely linked to cancer. Primaquine (PQ) was reported to impede autophagy flow by preventing autophagosomes from fusing with lysosomes at the late stage of autophagy. It will lead to cellular metabolic collapse and programmed cell death. Excessive or extended autophagy enhances the efficacy of chemotherapeutic drugs in cancer prevention. The utilization of autophagy inhibition in conjunction with chemotherapy has become a prevalent and reliable approach for the safe and efficient treatment of cancer. In this work, an acid-sensitive nanoprodrug (O@PD) targeting CD44 receptors was produced using Schiff-base linkages or electrostatic interactions from oxidized hyaluronic acid (OHA), PQ, and doxorubicin (DOX). The CD44-targeting prodrug system in triple-negative breast cancer (TNBC) cells was designed to selectively release DOX and PQ into the acidic tumor microenvironment and cellular endosomes. DOX was employed to investigate the cellular uptake and ex-vivo drug distribution of O@PD nanoprodrugs. PQ-induced autophagy suppression combined with DOX has a synergistic fatal impact in TNBC. O@PD nanoprodrugs demonstrated robust anticancer efficacy as well as excellent biological safety, making them suitable for clinical use.

Histochemical studies on the distribution and accumulation of trans-polyisoprene in the rubber-producing plant Eucommia ulmoides.

Eucommia ulmoides rubber (EUR) is a high-quality natural rubber resource, which can be extracted from different organs of the Eucommia ulmoides tree. In this study, EUR was isolated from the leaves, barks, and pericarps, and the structural characteristics and physicochemical properties of EUR were systematically determined. The accumulation and distribution of EUR in different tissues were assessed through in situ observations combined with cellular and subcellular scales. The preliminary analyses indicated that the variations in the physicochemical properties of EUR across different tissues were associated with its accumulation microstructure. Further analyses by SEM and TEM showed that the initial cell differentiation and fusion resulted in the formation of tubular structures without any nucleus. A limited number of rubber particles were generated within the cytoplasm, concurrent with aggregation and fusion. Eventually, rubber particles filled the entire cytoplasm, and organelles disappeared to form highly aggregated filamentous structures. In addition, the number and area of EUR-containing cells were closely related to the organization sizes of barks and leaves. This study provided valuable insights into Eucommia ulmoides histology and the rubber industry.

Family History of Type 2 Diabetes and Its Association with Beta Cell Function and Lipid Profile in Newly Diagnosed Pediatric Patients with Type 1 Diabetes.

OBJECTIVE: The objective of this study was to explore the associations between a family history of type 2 diabetes (T2D) and beta-cell function, as well as lipid profile, in pediatric patients newly diagnosed with type 1 diabetes (T1D). METHODS: A retrospective analysis was conducted on children under 14 years of age who were newly diagnosed with T1D at the Children's Hospital of Zhejiang University between August 2018 and August 2022. Clinical features, metabolic profiles, beta-cell function, and lipid profile were evaluated. RESULTS: A total of 316 children were diagnosed with new-onset T1D. Among them, 28.2% had a family history of T2D. Patients with T1D who had a family history of T2D experienced a later onset of the disease (p = 0.016), improved HOMA2-%B levels (p = 0.003), and increased concentrations of HDL-C (p = 0.005). In addition, no statistically significant differences in age at onset, HOMA2-%B levels, or HDL-C were found when assessing the interaction between family history of T2D and type of diabetes mellitus (autoimmune T1D/idiopathic T1D). CONCLUSION: A family history of T2D may contribute to the heterogeneity of T1D patients in terms of HOMA2-%B levels and lipid profile. This highlights the significance of taking into account T2D-related factors in the diagnosis and treatment of T1D.

Gene variants and clinical characteristics of children with sitosterolemia.

OBJECTIVE: To enhance the detection, management and monitoring of Chinese children afflicted with sitosterolemia by examining the physical characteristics and genetic makeup of pediatric patients. METHODS: In this group, 26 children were diagnosed with sitosterolemia, 24 of whom underwent genetic analysis. Patient family medical history, physical symptoms, tests for liver function, lipid levels, standard blood tests, phytosterol levels, cardiac/carotid artery ultrasounds, fundus examinations, and treatment were collected. RESULTS: The majority (19, 73.1%) of the 26 patients exhibited xanthomas as the most prevalent manifestation. The second most common symptoms were joint pain (7, 26.9%) and stunted growth (4, 15.4%). Among the 24 (92.3%) patients whose genetics were analyzed, 16 (66.7%) harbored ABCG5 variants (type 2 sitosterolemia), and nearly one-third (8, 33.3%) harbored ABCG8 variants (type 1 sitosterolemia). Additionally, the most common pathogenic ABCG5 variant was c.1166G > A (p.Arg389His), which was found in 10 patients (66.7%). Further analysis did not indicate any significant differences in pathological traits among those carrying ABCG5 and ABCG8 variations (P > 0.05). Interestingly, there was a greater abundance of nonsense variations in ABCG5 than in ABCG8 (P = 0.09), and a greater frequency of splicing variations in ABCG8 than ABCG5 (P = 0.01). Following a change in diet or a combination of ezetimibe, the levels of cholesterol and low-density lipoprotein were markedly decreased compared to the levels reported before treatment. CONCLUSION: Sitosterolemia should be considered for individuals presenting with xanthomas and increased cholesterol levels. Phytosterol testing and genetic analysis are important for early detection. Managing one's diet and taking ezetimibe can well control blood lipids.

Recent advances in super-resolution optical imaging based on aggregation-induced emission.

Super-resolution imaging has rapidly emerged as an optical microscopy technique, offering advantages of high optical resolution over the past two decades; achieving improved imaging resolution requires significant efforts in developing super-resolution imaging agents characterized by high brightness, high contrast and high sensitivity to fluorescence switching. Apart from technical requirements in optical systems and algorithms, super-resolution imaging relies on fluorescent dyes with special photophysical or photochemical properties. The concept of aggregation-induced emission (AIE) was proposed in 2001, coinciding with unprecedented advancements and innovations in super-resolution imaging technology. AIE probes offer many advantages, including high brightness in the aggregated state, low background signal, a larger Stokes shift, ultra-high photostability, and excellent biocompatibility, making them highly promising for applications in super-resolution imaging. In this review, we summarize the progress in implementation methods and provide insights into the mechanism of AIE-based super-resolution imaging, including fluorescence switching resulting from photochemically-converted aggregation-induced emission, electrostatically controlled aggregation-induced emission and specific binding-regulated aggregation-induced emission. Particularly, the aggregation-induced emission principle has been proposed to achieve spontaneous fluorescence switching, expanding the selection and application scenarios of super-resolution imaging probes. By combining the aggregation-induced emission principle and specific molecular design, we offer some comprehensive insights to facilitate the applications of AIEgens (AIE-active molecules) in super-resolution imaging.

Ultraconformable Integrated Wireless Charging Micro-Supercapacitor Skin.

Conformable and wireless charging energy storage devices play important roles in enabling the fast development of wearable, non-contact soft electronics. However, current wireless charging power sources are still restricted by limited flexural angles and fragile connection of components, resulting in the failure expression of performance and constraining their further applications in health monitoring wearables and moveable artificial limbs. Herein, we present an ultracompatible skin-like integrated wireless charging micro-supercapacitor, which building blocks (including electrolyte, electrode and substrate) are all evaporated by liquid precursor. Owing to the infiltration and permeation of the liquid, each part of the integrated device attached firmly with each other, forming a compact and all-in-one configuration. In addition, benefitting from the controllable volume of electrode solution precursor, the electrode thickness is easily regulated varying from 11.7 to 112.5 µm. This prepared thin IWC-MSC skin can fit well with curving human body, and could be wireless charged to store electricity into high capacitive micro-supercapacitors (11.39 F cm-3) of the integrated device. We believe this work will shed light on the construction of skin-attachable electronics and irregular sensing microrobots.

Biochemical and Transcriptome Analyses Reveal a Stronger Capacity for Photosynthate Accumulation in Low-Tillering Rice Varieties.

Moderate control of rice tillering and the development of rice varieties with large panicles are important topics for future high-yield rice breeding. Herein, we found that low-tillering rice varieties stopped tillering earlier and had a larger leaf area of the sixth leaf. Notably, at 28 days after sowing, the rice seedlings of the low-tillering group had an average single-culm above-ground biomass of 0.84 g, significantly higher than that of the multi-tillering group by 56.26%, and their NSC (non-structural carbohydrate) and starch contents in sheaths were increased by 43.34% and 97.75%, respectively. These results indicated that the low-tillering group of rice varieties had a stronger ability to store photosynthetic products in the form of starch in their sheaths, which was thus more beneficial for their large panicle development. The results of carbon and nitrogen metabolism analyses showed that the low-tillering group had a relatively strong carbon metabolism activity, which was more favorable for the accumulation of photosynthesis products and the following development of large panicles, while the multi-tillering group showed relatively strong nitrogen metabolism activity, which was more beneficial for the development and formation of new organs, such as tillers. Accordingly, in the low-tillering rice varieties, the up-regulated genes were enriched in the pathways mainly related to the synthesis of carbohydrates, while the down-regulated genes were mainly enriched in the nitrogen metabolism pathways. This study provides new insights into the mechanism of rice tillering regulation and promotes the development of new varieties with ideal plant types.

Towards Optical Information Recording: A Robust Visible-Light-Driven Molecular Photoswitch with the Ring-Closure Reaction Yield Exceeding 96.3 .

Diarylethene molecular photoswitches hold great fascination as optical information materials due to their unique bistability and exceptional reversible photoswitching properties. Conventional diarylethenes, however, rely on UV light for ring-closure reactions, typically with modest yields. For practical application, diarylethenes driven by visible lights are preferred but achieving high ring-closure reaction yield remains a significant challenge. Herein, we synthesized a novel all-visible-light-driven photoswitch, TPAP-DTE, by facilely endcapping the dithienylethene (DTE) core with triphenylamine phenyl (TPAP) groups. Owing to the electron-donating conjugation effect of TPAP, the open-form TPAP-DTE responds strongly to short-wavelength visible lights with considerable photocyclization quantum yields and molar absorption coefficient. Upon 405 nm visible-light irradiation, TPAP-DTE achieves a ring-closure reaction yield exceeding 96.3 % (confirmed by both nuclear magnetic resonance spectroscopy and high-performance liquid chromatography). Its ring-opening reaction yield is 100 % upon irradiation with long-wavelength visible light. TPAP-DTE could be regarded as a bidirectional "quasi"-quantitative conversion molecular switch. Furthermore, TPAP-DTE exhibits robust fatigue resistance over 100 full photoswitching cycles and great anti-aging property under 85 °C and 85 % humidity for at least 1000 h. Consequently, its rewritable QR-code, multilevel data storage, and anti-counterfeiting/encryption applications are successfully demonstrated exclusively using visible lights, positioning TPAP-DTE as a highly promising medium for information recording.

Room-Temperature Synthesis of Carbon-Nanotube-Interconnected Amorphous NiFe-Layered Double Hydroxides for Boosting Oxygen Evolution Reaction.

The oxygen evolution reaction (OER) is a key half-reaction in electrocatalytic water splitting. Large-scale water electrolysis is hampered by commercial noble-metal-based OER electrocatalysts owing to their high cost. To address these issues, we present a facile, one-pot, room-temperature co-precipitation approach to quickly synthesize carbon-nanotube-interconnected amorphous NiFe-layered double hydroxides (NiFe-LDH@CNT) as cost-effective, efficient, and stable OER electrocatalysts. The hybrid catalyst NiFe-LDH@CNT delivered outstanding OER activity with a low onset overpotential of 255 mV and a small Tafel slope of 51.36 mV dec-1, as well as outstanding long-term stability. The high catalytic capability of NiFe-LDH@CNT is associated with the synergistic effects of its room-temperature synthesized amorphous structure, bi-metallic modulation, and conductive CNT skeleton. The room-temperature synthesis can not only offer economic feasibility, but can also allow amorphous NiFe-LDH to be obtained without crystalline boundaries, facilitating long-term stability during the OER process. The bi-metallic nature of NiFe-LDH guarantees a modified electronic structure, providing additional catalytic sites. Simultaneously, the highly conductive CNT network fosters a nanoporous structure, facilitating electron transfer and O2 release and enriching catalytic sites. This study introduces an innovative approach to purposefully design nanoarchitecture and easily synthesize amorphous transition-metal-based OER catalysts, ensuring their cost effectiveness, production efficiency, and long-term stability.

Fluorescent Materials with Excellent Biocompatibility and Their Application in Bio-Sensing, Bio-Imaging.

Fluorescent materials have great potential for use in biomedical applications due to their ease of functionalization and tunable fluorescence color [...].

Efficient separation and production of high-quality rubber, lignin nanoparticles and fermentable sugars from Eucommia ulmoides pericarp via deep eutectic solvent pretreatment.

The natural barriers of lignocellulose hinder the separation of Eucommia ulmoides rubber (EUR) from Eucommia ulmoides pericarp (EUP), whereas traditional separation methods normally lead to the waste of Eucommia ulmoides lignocellulose resource and environmental pollution. In this study, an acidic deep eutectic solvent composed of lactic acid and ZnCl2 was developed as a pretreatment medium to reduce the separation barriers of EUR while producing lignin nanoparticles and fermentable sugars. Results showed that DES pretreatment could accelerate the extraction efficiency (91.0 %) and purity (>99 %) of EUR and maintain its chemical structure compared to the traditional alkaline and mechanical methods. Meanwhile, the regenerated nano-lignin showed excellent antioxidant activity (IC50 = 46.3 µg/mL) comparable to commercial antioxidant BHA. Besides, the enzymatic hydrolysis efficiency of EUP with DES pretreatment was significantly enhanced about 9 times than the control groups. Overall, the acidic DES pretreatment could be considered a promising pretreatment method for separation of high-quality EUR and valorization of lignocellulosic components.

Research on the Differences in Phenotypic Traits and Nutritional Composition of Acer Truncatum Bunge Seeds from Various Regions.

Acer truncatum Bunge (ATB) is an excellent edible woody oil tree species since it bears a huge amount of fruit and has strong adaptability to be widely cultivated. Selecting an optimal cultivation region for ATB is crucial to improving China's woody oil industrialization. Chemical analysis, correlation analysis, and affiliation function values were used in the present research to systematically analyze the phenotypic traits, organic compound content, and seed oil chemical composition of the seeds of ATB from nine regions. The average contents of oil, protein, and soluble sugar in ATB seeds were 43.30%, 17.40%, and 4.57%, respectively. Thirteen fatty acids were identified from ATB seed oil, the highest content of which was linoleic acid (37.95%) and nervonic acid content was 5-7%. The maximum content of unsaturated fatty acids in ATB seed oil was 90.09%. Alpha-tocopherol content was up to 80.75 mg/100 g. The degree of variation in seed quality traits (25.96%) was stronger than in morphological traits (14.55%). Compared to environmental factors, the phenotypic traits of seeds contribute more to organic compounds and fatty acids. Combining the values of the indicator affiliation functions, Gilgarang, Tongliao, Inner Mongolia was selected as the optimal source of ATB for fruit applications from nine regions.

Mannose-Binding Lectin Reduces Oxidized Low-Density Lipoprotein Induced Vascular Endothelial Cells Injury by Inhibiting LOX1-ox-LDL Binding and Modulating Autophagy.

Objective: To investigate the role of mannose-binding lectin (MBL) in modulating autophagy and protecting endothelial cells (ECs) from oxidized low-density lipoprotein (ox-LDL)-induced injury. Methods: Serum MBL concentration and carotid intima-media thickness (cIMT) were measured in 94 obese and 105 healthy children. ECs were transfected with MBL over-expression plasmid, LOX1 was knocked-down to explore the protective role of MBL in ox-LDL induced ECs injury. Dendritic cells (DCs) were co-cultured with ECs, and inflammatory factors, DC maturation, and autophagy was assessed. WT and ApoE-/- mice were fed with a high fat diet (HFD) with or without MBL-adenovirus injection for 16 weeks and aortic vascular endothelial tissue was isolated, then atherosclerotic plaque, cell injury and autophagy were analyzed. Results: Serum MBL concentration in obese children was lower than healthy controls and was negatively correlated with cIMT. The uptake of ox-LDL was decreased in LOX1 knock-down ECs. MBL over-expression in vitro inhibited LOX1-ox-LDL binding. Both LOX1 knock-down and MBL over-expression can ameliorate EC autophagy and cell injury. MBL over-expression in vivo alleviated atherosclerotic plaque formation, influenced DC maturation and down-regulated IL-6, IL-12, and TNF-a levels. Conclusions: MBL exerts a protective role in ox-LDL-induced EC injury by modulating DC maturation and EC autophagy via inhibiting LOX1-ox-LDL binding.

Low-temperature torrefaction assisted with solid-state KOH/urea pretreatment for accelerated methane production in wheat straw anaerobic digestion.

Low-temperature torrefaction assisted with solid-state KOH/urea applied onto wheat straw was proposed to break down the lignocellulosic material to enhance biomethane production in anaerobic digestion (AD). The optimization of key parameters applying the Box-Behnken design and response surface methodology showed that an addition of 0.1 g/gstraw KOH/urea at 180 °C while torrefying for 30 min was the optimal condition for producing biomethane. Results indicate that co-applying KOH and urea in torrefaction synergistically enhanced the biodegradability of straw by effectively removing lignin and largely retaining cellulose, giving rise to a 41 % increase in the cumulative methane production compared to untreated straw (213 mL/g-volatile solids (VSraw)) from batch AD. Additionally, the nitrogen- and potassium-rich digestates helped to improve soil fertility, thus achieving a zero-waste discharge. This study demonstrated the feasibility of using solid-state KOH/urea assisted low-temperature torrefaction as an effective pretreatment method to promote methane production during AD.

Rational Design of High-Performance Hemithioindigo-Based Photoswitchable AIE Photosensitizer and Enabling Reversible Control Singlet Oxygen Generation.

A photosensitizer furnishing with reversible control singlet oxygen generation (1O2) is highly desirable for precise photodynamic therapy (PDT), lessening non-specific harm to healthy tissues. Here, a novel photoswitchable aggregation-induced emission (AIE) photosensitizer based on a triarylamine (TPA)-modified hemithioindigo (HTI), 6Br-HTI-TPA-OMe, was rationally designed. The triarylamine AIE photosensitizing moiety and HTI switch unit were covalently linked in one molecule, permitting reversible regulation of 1O2 production. The photophysical evaluations revealed that 6Br-HTI-TPA-OMe possessed excellent AIE properties and Z/E photoswitch performance in different solvents. Additionally, the amphiphilic phospholipid-fabricated nanoparticles (NPs) also exhibited photochromic behavior in water. The Z-NPs initiated the generation of 1O2 upon 520 nm light-emitting diode (LED) irradiation, but after switching to E-NPs, the generation of 1O2 was inhibited by the competitive energy transfer, suggesting that reversible Z/E isomerization could photocontrol 1O2 generation. The in vitro anti-tumor experiment verified that the 6Br-HTI-TPA-OMe can act as a photoswitchable AIE photosensitizer. This is the first report on the photoswitchable AIE photosensitizer of HTI-based molecules, to the best of our knowledge.

"Potential Scalpel": A Bioassisted Ultrafast Staining Lateral Flow Immunoassay from De Novo to Results.

It is of great importance to overcome potential incompatibility problems between dyestuffs and antibodies (mAbs) for extensive commercial application of a dyestuff-chemistry-based ultrafast colorimetric lateral flow immunoassay (cLFIA). Herein, inspired by traditional staining technologies, a basic dyestuff gallocyanine (GC)-assisted biogenic "potential scalpel"-based cLFIA (GC-ABPS-based cLFIA) by employing clenbuterol (CLE) as proof-of-concept was proposed to solve a high degree of incompatibility between the same potential dyestuffs and mAbs. Goat antimouse immunoglobulin (Ab2) could serve as the "potential scalpel" to form the positive potential value biomolecular network self-assemblers (BNSA) with anti-CLE mAbs (AbCLE) by noncovalent force. The cLFIA completed the entire detection process from de novo to detection results within 30 min thanks to the easy availability and ideal marking efficiency (≤1 min, saving 0.4-10 h) of GC. Encouragingly, the proposed ultrafast GC-ABPS-based cLFIA has also exhibited high sensitivity (0.411 ng mL-1) and low cost (300 times) compared with other cLFIAs. Also, the feasibility of the proposed cLFIA was demonstrated by detecting CLE in beef, pork ham, and skim milk. Finally, the proposed GC-ABPS-based cLFIA has broadened the application range of dyestuffs and provided an effective reference strategy for the application of dyestuffs in food safety monitoring.

Schiff-Base Chemistry-Coupled Catechol Oxidase-Like Nanozyme Reaction as a Universal Sensing Mode for Ultrasensitive Biosensing.

Expanding sensing modes and improving catalytic performance of nanozyme-based analytical chemistry are beneficial to realizing the desired biosensing of analytes. Herein, Schiff-base chemistry coupled with a novel catechol oxidase-like nanozyme (CHzyme) is designed and constructed, exhibiting two main advantages, including (1) improving catalytic performance by nearly 2-fold compared with only the oxidase-like role of CHzyme; (2) increasing the designability of the output signal by signal transduction of cascade reaction. Thereafter, the substrate sensing modes based on a cascade reaction between the CHzyme-catalyzed reaction and Schiff-base chemistry are proposed and comprehensively studied, containing catalytic substrate sensing mode, competitive substrate sensing mode, and generated substrate sensing mode, expecting to be employed in environmental monitoring, food analyses, and clinical diagnoses, respectively. More meaningfully, the generated substrate sensing mode is successfully applied to construct a cascade reaction coupling ratiometric fluorescent immunoassay for the detection of clenbuterol, increasing 15-fold in detection sensitivity compared with the traditional enzyme-linked immunosorbent assay. It is expected that the expanded universal substrate sensing modes and the Schiff-base chemistry-enhanced nanozyme can enlighten the exploration of innovative biosensors.