Antibiotics in the environment readily adsorb onto small surface-area plastic surfaces, generating coexisting pollutants that pose greater risks than individual pollutants. Here, we developed a three-dimensional envelope-enhanced SERS platform (3D EES) strategy for the detection and quantification of coexisting pollutants by integrating surface-enhanced Raman spectroscopy (SERS) with machine learning (ML). The 3D EES strategy was established using three-phase interface self-assembly to organize Au@Ag plasmonic nanoparticles into a hydrophobic array substrate, generating dense and uniform plasmonic gap hot spots. The coconcentration of coexisting pollutants and plasmonic nanoparticles on the hydrophobic array substrate generated additional hotspots, further amplifying the SERS signal. This strategy enabled the detection of antibiotics adsorbed onto polystyrene (PS) at concentrations as low as 250 ng/L. A comprehensive SERS data set of coexisting pollutants was constructed, and machine-learning models (SNE-SVM and RF-SVM) achieved 98.07% accuracy and 96.44% Jaccard similarity, allowing reliable classification of antibiotic species adsorbed on plastic and accurate prediction of their adsorption levels. This method provides a robust tool for identifying coexisting pollutants in complex environments and offers new opportunities for tracing pollutant sources and understanding their environmental migration and transformation.

Narrow-bandgap semiconductors with non-centrosymmetric structures, while responsive to visible light, often exhibit limited photocatalytic CO2 reduction performance due to poor quantum efficiency and insufficient thermodynamic driving force. Here, we demonstrate a compelling strategy to repurpose these "dormant" materials as efficient piezocatalysts through mechanical activation. Two-dimensional Cu2MoS4 (CMS), a material with weak photocatalytic activity, exhibits CO-dominant piezocatalytic CO2 reduction under vibration, delivering a CO production rate more than two orders of magnitude higher than that of its photocatalytic counterpart under equivalent nominal power input, together with a substantially improved apparent energy-normalized performance. The piezoelectric properties of CMS were confirmed by piezoelectric force microscopy, piezocurrent measurements, and direct d33 quantification. Finite element analysis indicates that CMS can generate a piezopotential sufficient to drive CO2 reduction, while density functional theory calculations show that mechanical stress induces a more negative conduction band edge, enhances electron density at sulfur active sites, and lowers the Gibbs free energy barrier for the *COOH-to-*CO step. Under optimized conditions, the CMS nanosheets achieved a CO evolution rate of 594.3 μmol g-1 h-1 without cocatalysts. This mechanically driven approach unlocks the catalytic potential of underperforming non-centrosymmetric semiconductors and offers a promising route for sustainable CO2 conversion through mechanical energy harvesting.

The rapid recombination of photogenerated carriers and the limited visible light absorption of conventional single-component photocatalysts restrict their effectiveness in practical pollutant degradation. To address these limitations, we synthesized a novel S-scheme heterojunction photocatalyst, MIL-125-NH2@CoFe PBA (M@P), by employing a direct MOF-on-MOF strategy that utilizes Ti-MOF and Co-MOF. The S-scheme heterojunction significantly mitigated charge recombination while facilitating the transport of photogenerated carriers through the formation of high-speed transport orbitals via Ti-O-Co bonds, thereby enhancing the activation of persulfate (PMS). This synergy enabled efficient degradation of recalcitrant pollutants. Using sulfamethoxazole (SMX) as a benchmark, our system achieved a remarkable 92.72 % removal rate of SMX within 45 min, resulting in a degradation rate constant of 0.0457 min(-1) under optimized conditions. Further investigations, including free radical trapping experiments and electron paramagnetic resonance (EPR) analysis, confirmed that the primary contributors to degradation were the photogenerated holes (h+). Additionally, liquid chromatography-mass spectrometry (LC-MS) elucidated the degradation pathway of SMX. In summary, this study explored the carrier-directed migration mechanism of S-scheme heterojunctions, guiding the construction of heterostructures specifically designed for the efficient degradation of emerging pollutants. These insights provided valuable theoretical foundations for advancing photocatalytic wastewater treatment technologies.

Electrochemical conversion of CO2 to multi‑carbon (C2) products is constrained by sluggish carbon‑carbon bond formation reactions and linear scaling relationships between intermediate binding energies. Herein, we report a dual-level microenvironment engineering strategy to overcome these bottlenecks by integrating tandem catalysis within a spatially confined and electronically modulated architecture. Specifically, Pd-doped Cu2O hollow nanospheres were assembled onto pyridine (Py) functionalized V2C MXene (V2C-Py@Cu2O-Pd). In this hierarchical design, the hollow nanoreactors confine the intermediates, elevating the local *CO concentration generated by the Pd tandem sites. Meanwhile, the highly conductive V2C-Py scaffold improves charge transport and stabilizes the hybrid interface via Py anchoring, collectively regulating the interfacial electron microenvironment. The optimized catalyst delivered a C2 product faradaic efficiency (FE) of 79.7% ± 2.5% in an H-cell and, in a flow cell, achieved total current density (jtotal) of 477.2 ± 13.5 mA cm-2 with an ethylene FE of 48.2% ± 3.2%. In situ Raman spectroscopy and density functional theory (DFT) calculations reveal that an increased proportion of restricted rotation (P1) versus stretched adsorption (P2) CO species corresponds to higher *CO coverage, lowering the energy barrier for formation of crucial intermediates and facilitating CC coupling. These findings demonstrate that combining micro-environmental regulation with tandem catalysis is an effective strategy for improving selective CO2-to-C2 conversion.

Nanozymes offer significant advantages, including high stability, straightforward synthesis, and low cost, positioning them as viable alternatives to natural enzymes. However, the limited variety and specificity of nanozymes have been a persistent challenge. In this study, we developed a copper metal-organic framework material (Cu-MOF) using poly(acrylic acid) nanoparticles (PAA NPs) as a structural core. We innovatively discovered that sulfonamides (SAs) can function as coenzymes to activate the oxidase-like activity of Cu-MOF. Through multiple experimental approaches, the mechanism underlying the coenzyme-like function of SAs was investigated. The high affinity between SAs and Cu-based nanozymes serves as the substrate-driven foundation, promoting the generation of multiple reactive oxygen species and collaborating with electron transfer processes to accomplish catalytic oxidation. This discovery provides insights for broadening nanozyme substrate diversity and enhancing nanozyme specificity. Given that SAs are among the most widely used antibiotics, their environmental implications necessitate careful consideration. To address this, we concurrently designed a colorimetric sensing system for SAs based on the Cu-MOF nanozyme, integrating it with smartphone camera functionality to enable RGB detection. Additionally, by applying principal component analysis (PCA) to the RGB data, we achieved simultaneous detection and identification of multiple SAs, even in mixed samples. The present study proposes a substrate-driven nanozyme coenzyme theory, also highlights the potential of smartphone-integrated colorimetric sensors for effective visualization and high-throughput detection, thereby broadening the application scope of nanozyme.

Current strategies for microRNAs (miRNAs) detection in live-cell imaging are hindered by several methodological limitations, including poor delivery efficiency, inadequate signal amplification, insufficient target specificity, and overly complex reaction architectures. To address these issues, we present a streamlined cascade logic system mediated by multilayered metal-organic framework nanomaterials (PCZF-8), which integrates catalytic hairpin assembly (CHA) and DNAzyme sequences for the fluorescent detection of endogenous intracellular miRNAs (miR-21 and miR-155) and enables precise cancer cell identification. Central to this approach is a bifunctional double-loop hairpin probe (H1) that incorporates both miRNA recognition sequences and a DNAzyme motif, endowing it with dual capabilities for target binding and catalytic signal generation. Upon recognition of miR-21 and miR-155, the CHA-DNAzyme cascade amplification reaction is effectively triggered, enabling rapid cleavage of a fluorogenic substrate probe (H3) and a robust fluorescent output. Remarkably, the entire dual miRNAs recognition, CHA-DNAzyme cascade amplification, and logic-gated response are achieved with only three hairpin components (H1, H2, and H3), underscoring the system's molecular economy and design elegance. The assay achieves femtomolar (fM) detection limits for both miR-21 and miR-155 and operates as an AND-gated logic circuit, selectively identifying breast cancer cells based on their characteristic coexpression profile of these miRNAs. Furthermore, the intrinsic pH-responsive fluorescence property of PCZF-8 enhances cellular discrimination by distinguishing the acidic tumor microenvironment of cancer cells from that of normal cells. By synergistically combining nanomaterial engineering with molecular logic and cascade amplification, this platform establishes a novel paradigm for intelligent, highly specific cancer diagnostics in live-cell settings.

Chiral recognition sensing is pivotal in pharmaceutical synthesis and biomedical applications, yet three key challenges persist: the inability to simultaneously achieve high-resolution identification and characterization of enantiomers, insufficient understanding of the molecular mechanisms governing chiral recognition, and limited efficacy in analyzing complex mixtures of chiral compounds. Here, we present a supramolecular plasmonic nanoparticle-on-mirror (NPoM) platform for surface-enhanced Raman scattering (SERS) chiral sensing. By employing sulfhydryl-functionalized β-cyclodextrin (β-CD) as a supramolecular core for selective chiral amino acid capture, the platform facilitates the precise formation of a ∼1.2 nm plasmonic nanogap hotspot between gold nanoparticles (AuNPs) and a gold film (AuF). This configuration significantly enhances enantiomer-specific Raman signals, thereby enabling high-resolution identification and enantioselective discrimination of aromatic amino acid enantiomers. Density functional theory (DFT) calculations reveal the chiral recognition mechanism: β-CD forms diastereomeric complexes with d- and l-enantiomers through distinct spatial configurations and differential binding affinities, resulting in characteristic spectral differences that enable precise enantioselective identification. Furthermore, integration with machine learning (ML) algorithms facilitates rapid, highly accurate enantiomer classification and robust blind prediction of unknown samples. Notably, the proposed platform demonstrates exceptional performance in the simultaneous discrimination of complex enantiomeric mixtures comprising multiple chiral aromatic amino acids, providing a powerful strategy for advanced chiral analysis.

Elucidating the "anti-poisoning" mechanism of palladium (Pd) alloy catalysts in the CO2 reduction reaction (CO2RR) has long been impeded by the lack of direct spectroscopic observation of surface intermediates. Herein, by engineering bifunctional Au@AgPd core-shell nanoreactors with a "borrowing SERS" strategy, we bypass the SERS-inactive limitation of Pd and successfully capture the dynamic evolution of key species. Crucially, in situ spectroscopic monitoring reveals a striking adsorption destabilization phenomenon: Ag doping dramatically weakens the binding affinity of carbon intermediates, thereby suppressing the accumulation of poisoning species (*COOH) on the Pd surface. Corroborated by density functional theory and density of states analysis, this effect is attributed to the downward shift of the Pd d-band center, which modulates the adsorption strength of carbon species to a moderate range. Guided by this molecular-level insight, the optimized catalyst achieves precise synthesis of syngas with widely tunable H-2/CO ratios (4.04-0.24) and exceptional stability (>60 h), providing a robust paradigm for rationally designing CO-tolerant catalysts.

2-Arylindoles are important motifs that serve as key components in a large variety of biologically active molecules and pharmaceuticals. Herein, we report a photoredox/Co-catalysis-enabled regioselective C2-arylation of indoles. This protocol allows for facile construction of a series of 2-arylindoles from structurally varied indoles and various aryl halides, featuring excellent regioselectivity, broad substrate scope, and good reaction efficiency. Mechanistically, the rational combination of photoredox-driven halogen-atom transfer (XAT) and Co-mediated desaturation ensured the success of this newly developed methodology.

Precise identification of tumor cells is paramount for disease diagnosis and treatment, where tumor markers play a pivotal role. However, relying solely on a single tumor marker detection method often falls short in differentiating various types of tumor cells, leading to potential false-positive signals. To address this challenge, we have developed a ternary DNA logic gate system. This logic circuit is supported by multi-aptamers and performs identification operations by targeting different cell surface proteins. It fully leverages the functionality and framework characteristics of DNA nanostructures, employing a Toehold-Mediated Strand Displacement (TMSD) cascade amplification reaction to convert the strand signal into an electrical signal. This integrated multi-module ternary DNA logic gate system demonstrates accurate recognition among six cell lines while achieving highly sensitive detection of target tumor cells. Biosensors that integrate DNA logic computing with aptamers not only facilitate accurate tumor cell identification but also exhibit significant potential in the realms of drug delivery and cancer therapy.

Electrochemical sensors are often limited in stability and reliability due to influences such as probe modification density and electrode surface degradation. This study constructed an electrochemical ratiometric biosensor based on framework nucleic acid (FNA), cascade catalytic hairpin assembly (CHA), and hybridization chain reaction (HCR), achieving efficient and accurate detection of miRNA-21. Compared to traditional one-dimensional DNA electrochemical ratiometric sensors, the strong rigidity of FNA prevents probe entanglement and enhances the stability of reference probes. Notably, the introduction of a bulge loop structure provides the framework with better functional versatility. Furthermore, the application of cascade amplification endows the ratiometric sensor with enhanced adaptability for detecting low-abundance targets. By employing this sensing approach, miRNA-21 can be quantified across an extensive linear concentration range (100 aM to 100 pM), with a detection limit of 45 aM. Compared to conventional ratiometric sensors, the proposed self-sustaining FNA-based electrochemical ratiometric sensor demonstrates superior stability, accuracy, and sensitivity, showing great potential for applications in bioanalysis and medical diagnostics.

Herein, the C2-selective bis(trifluoromethyl)carbination of quinolines was accomplished, which is enabled by a rationally designed PCET/copper-mediated radical cross-coupling Minisci-type reaction. This synergistic strategy provides facile access to a broad range of previously inaccessible bis(trifluoromethyl)carbinolized quinolines by using readily available hexafluoroacetone hydrate instead of toxic gaseous hexafluoroacetone. The success of this transformation complements the reaction mode and extends the boundary for the classic Minisci-type reaction by surpassing the intrinsic challenge in the radical addition for the polarity-mismatched radical species with heteroarenes. Notable features of this method include operational simplicity, mild reaction conditions, excellent regioselectivity, and a broad functional group tolerance. A combination of experimental and theoretical studies was extensively conducted to investigate the reaction pathway.

The simultaneous detection of emerging contaminants antibiotics in complex environmental samples remains a major analytical challenge due to the complexity of the samples and interference from overlapping fingerprint characteristics in practical application scenarios. This study introduces a glass capillary platform utilizing Surface-enhanced Raman scattering (SERS) for the microsampling detection of five antibiotics in complex environments. The glass capillary serves as an ideal carrier to provide the large surface area and enhance sensitivity by exploiting the intrinsic waveguide effect of the material. To further improve SERS capacity, the activated glass capillary was modified with silver nanoparticles stabilized by a PVP solution, resulting in a SERS-activated capillary sensing platform capable of detecting a variety of antibiotics in real samples with a limit of detection (LOD) as low as of 7.62 × 10-9 M. By employing principal component analysis (PCA) and machine learning (ML) algorithms, we successfully separated the multiplexed SERS data for five different antibiotics mixed in various ratios with real samples, achieving a classification accuracy of 99 % using SVM model, even at microliter-scale sample volumes. This demonstrates that SERS-activated capillary sensors can effectively identify and characterize different antibiotics, thereby offering a promising solution for the simultaneous detection of multiple antibiotics in complex environments.

Direct C-H alkylation is one of the most important C-C bond formation events and is crucial to the efficient assembly of functionalized carbon skeletons in synthetic chemistry. We report herein a photoinduced palladium-catalyzed strategy for the direct alkylation of allylic C-H bonds. The success of this transformation relies on the use of 2-bromo-1,3-dimethylbenzene as a hydrogen atom transfer (HAT) mediator, in combination with a carbon nucleophile, facilitated by a palladium catalyst activated by blue light. Unlike classical Pd(II/0) pathways, this approach leverages the versatile reactivity of Pd(0/I/II) species through visible-light excitation, establishing a robust foundation for the feasibility of this synthetic methodology.

Research on nanoplastic (NP) toxicity and their "carrier effects" on human health remains nascent, especially for real-time, in situ monitoring of metabolic reactions in live cells. Herein, we developed smart surface-enhanced Raman spectroscopy (SERS) slides using a cyclic centrifugation-enhanced electrostatic loading (CCEL) method to facilitatively track live-cell metabolic signals. The designed core-shell polystyrene NPs (mPS) with embedded Raman probes successfully identified intracellular accumulation via a distinct Raman-silent peak. The smart SERS slide effectively monitored the metabolic changes induced by mPS at the molecular level, distinguishing different stages of membrane interaction, the endocytosis process, endosomal aggregation, and cell apoptosis. Besides, this platform was employed to perform a real-time, in situ comparison of cell cycle alterations induced by bare NPs and their "carrier effects", revealing that NPs extended both the S and G2 phases in BEAS-2B cells, while the "carrier effects" further prolonged G2 and disrupted S-phase progression. Additionally, we integrated machine learning algorithms to accurately predict the cell cycle impacts associated with mPS and their "carrier effects". This study provides a label-free, in situ, real-time method for monitoring NP-induced metabolic changes in live cells, laying the groundwork for further investigation into cytotoxic behaviors and strategies to mitigate NP toxicity.

Objective: To establish a green and efficient extraction process for total flavonoids from Robinia pseudoacacia L. flos using ultrasound-assisted deep eutectic solvents (DESs), optimize the process using response surface methodology, and systematically evaluate their in vitro antioxidant activities, providing experimental evidence for the development and utilization of active components in Robinia pseudoacacia flowers. Methods: Choline chloride was used as the hydrogen bond acceptor (HBA), and 1,2-propanediol, ethylene glycol, and lactic acid were used as hydrogen bond donors (HBD) to prepare three DES systems. Single-factor experiments were conducted to investigate the effects of HBA: HBD molar ratio, water content, liquid-to-solid ratio, ultrasonic time, and temperature on the extraction rate of total flavonoids. The extraction conditions were then optimized using Box-Behnken response surface design. High-performance liquid chromatography (HPLC) was used to determine the content of major flavonoid components (rutin, quercetin, and luteolin). The antioxidant capacity was evaluated by DPPH· and ABTS⁺ free radical scavenging rates. Results: Single-factor analysis showed that the highest extraction rate was achieved when the DES was choline chloride-1,2-propanediol (molar ratio 1:3), water-to-DES volume ratio was 3:1, liquid-to-solid ratio was 35:1 (mL/g), ultrasonic temperature was 65 ℃, and ultrasonic time was 40 min. Response surface optimization indicated that the theoretical extraction rate under these conditions was 4.26%, and the average value of the validation experiment was 4.22%, with an error of less than 1%. HPLC analysis revealed that the contents of rutin, quercetin, and luteolin were 2.06, 1.32, and 0.84 mg/g, respectively. Antioxidant experiments showed that when the extract concentration was 0.4 mg/mL, the scavenging rates of DPPH· and ABTS⁺ were 81.45% and 92.30%, respectively, with no significant difference compared to the vitamin C group (P>0.05). Conclusion: The established DES-ultrasound-assisted extraction method is green, environmentally friendly, and reproducible, significantly improving the extraction rate of flavonoids from Robinia pseudoacacia flowers. The extract has strong antioxidant capacity, providing a scientific basis for its application in the development of natural antioxidants.

Alcohols and carbonyl compounds are fundamental and abundant feedstock chemicals, whose orthogonal reactivities, aside from classical textbook chemistry, have been unstoppably pursued to overcome the limit of their inherent electronic features. Here we report a mild, photoredox-driven deoxygenative cross-coupling between benzylic alcohols and carbonyl compounds (aromatic aldehydes, aromatic ketones, and ketone esters). This well-designed open-shell chemistry rationally takes advantage of the photocatalytic generation of alkyl and ketyl radicals in a single photocatalysis cycle and PRE-directed radical-radical cross-coupling to forge the C-C bond formation, thereby offering direct access to sterically congested secondary and tertiary alcohols. The developed protocol delivers a broad range of benzylic-substituted alcohols in moderate to good yields by using abundant starting materials with high chemoselectivity, functional group tolerance, and operational simplicity. Mechanistic investigations and DFT calculations comprehensively support the radical-coupling process involving the concurrent generation of ketyl and benzyl radicals within a single photoredox cycle and chemoselective C-C bond formation.

The coexistence of cadmium (Cd) and antimony (Sb) in soils severely threatens environmental safety and human health. While biochar is widely used for soil remediation, its effectiveness in removing multiple metals, especially in the presence of anions, lacks dynamic quantification and mechanistic understanding. This study synthesized a MnFe2O4-biochar composite (MF-RBC) using the coprecipitation method, and explored its adsorption performance and mechanisms for coexisting Cd(II) and Sb(V). The maximum adsorption capacities of MF-RBC for Cd(II) and Sb(V) were 11.24 and 57.33 mg g-1, respectively, higher than those of pure RBC (6.27 mg g-1 for Cd(II), and 19.43 mg g-1 for Sb(V)) and MF (9.25 mg g-1 for Cd(II), and 48.01 mg g-1 for Sb(V). The enhanced performance is attributed to the large specific surface area of MF-RBC (318.86 m2 g-1), improved dispersion of MF particles by biochar, and the attachment of oxygen-containing groups. Additionally, Cd(II) exhibited a synergistic effect on Sb(V) removal, likely due to reduced negative charge repulsion between MF-RBC and Sb(V), and the formation of MF-Cd(II)-Sb(V) ternary complexes. MF-RBC also decreased the availability of Cd and Sb by transforming them into more stable forms. Microscopic and mechanistic analysis revealed that Cd(II) forms complexes with both the CO/CO groups of biochar and the MnO bonds of MnFe2O4, while Sb(V) is primarily complexed with FeO bonds of MnFe2O4 in the Cd&Sb coexistence system. These findings facilitate a better understanding of Cd(II) and Sb(V) behavior in natural environments and offer valuable insights for improving soil remediation strategies.

Antibiotic contamination has been a significant concern in environmental monitoring. Nanozyme-based colorimetric sensors can provide valuable support for in-field detection. However, the development of sensing elements capable of identifying an entire class of specific antibiotics using a single material poses a considerable challenge. In this work, we present a compartmentalized dual-nanozyme cascade composite (Au@mPDA/PAA-Cu2MI, AmPC) designed for the colorimetric detection of aminoglycoside antibiotics (AGs), and we analyze the catalytic mechanisms of the dual-enzyme system in detail. The AmPC composite possesses both analogue glucose oxidase-like (aGOx-like) and peroxidase-like (POD-like) activities. In this process, AGs with a sugar structure can serve as the initial substrate of the reaction, while the resulting H2O2 acts as the second substrate for colorimetric detection. Using gentamicin (GMC) as a proof of concept, we established a detection range of 0.1-10 μg/mL, with a detection limit (LOD) of 91 ng/mL. In addition, we validated the colorimetric response for other AGs and employed principal component analysis (PCA) for differentiating among various AGs. This approach enables nanozymes to selectively recognize their targets through a cascade mechanism. Furthermore, it facilitates the simultaneous detection and identification of antibiotics, highlighting its potential for in-field applications.