化学最新文献

Golgi protein 73 (GP73) is a clinically relevant biomarker associated with hepatocellular carcinoma (HCC). However, fluorescence-based quantification and intracellular imaging are susceptible to interference and signal instability in thiol-rich biological environments. Herein, we report a fluorescent aptamer nanosensor based on Au-Se anchoring, which integrates a mechanistically guided anti-interference design with a calibratable, buffer-based quantitative workflow for GP73 detection. The sensing interface translates GP73 recognition into fluorescence recovery via target-induced aptamer conformational switching and increased fluorophore-gold nanoparticle distance, while the Au-Se bond mitigates thiol-driven false activation. Under optimized conditions, the assay shows a linear response in the range of 0-800 ng/mL with a detection limit of 1.51 ng/mL. Stability and tolerance studies demonstrate its robust performance across a pH range of 6.2-8.0 and in the presence of physiologically relevant concentrations of glutathione. Notably, in 5 mM glutathione, the signal increases by less than 1.5-fold compared to the untreated control, and its performance is significantly superior to that of the conventional Au-S anchored probe. Specificity experiments confirm that the probe responds significantly only to GP73, showing negligible responses to a panel of non-target proteins and a scrambled aptamer control. Preliminary serum experiments further demonstrate feasibility in a 10× diluted human serum matrix, where the probe preliminarily differentiates GP73-positive HCC patient sera from sera of other cancer patients using a ΔF strategy to reduce serum background fluorescence; however, we emphasize that the cohort size is limited and larger clinical validation is required for definitive clinical claims. Cellular experiments reveal GP73-correlated fluorescence contrast between HepG2 and normal liver (THLE-2) cells, and the thiol-depletion control (N-ethylmaleimide) supports that intracellular signal activation is thiol-independent. In summary, this work provides a robust Au-Se-stabilized nanosensor for quantitative GP73 readout in buffer and cellular imaging under thiol-rich conditions. The control experiments clearly define its specificity and anti-interference advantages, delineating key practical operating boundaries and providing a foundation for future expanded validation in complex clinical matrices.

In this study, an 808 nm near-infrared (NIR)-responsive hydrogel (NOR-MSN@MnO₂-gel) was developed for the treatment of bacteria-infected wounds. The norfloxacin (NOR)-loaded manganese dioxide-modified mesoporous silica (NOR-MSN@MnO₂) nanoparticles were selected as a photothermal material and encapsulated in the furfuryl amine-modified hyaluronic acid hydrogel (HA-FA^gel). Studies found that MSN@MnO₂-gel exhibited a three-dimensional porous network structure, favorable injectability, excellent water absorption & retention capacity, and desirable photothermal conversion efficiency. Benefiting from pH/NIR dual-responsive characteristics, NOR-MSN@MnO₂-gel realized controllable NOR release and achieved efficient elimination of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) through synergistic photothermal therapy (PTT) and chemotherapy. In vivo infected wound studies demonstrated that NOR-MSN@MnO₂-gel combined with NIR irradiation (NOR-MSN@MnO₂-gel + NIR) could effectively inhibit bacterial growth, alleviate inflammation, accelerate re-epithelialization, and promote collagen deposition & angiogenesis, while maintaining satisfactory biological safety. Collectively, the NOR-MSN@MnO₂-gel + NIR regimen provides a promising strategy for clinical treatment of bacterial infected wounds.

The simultaneous determination of dopamine and uric acid in complicated biological matrices remains challenging due to overlapping electrochemical signals and interference from coexisting species. Herein, a machine learning-assisted electrochemical sensor based on a Cu₃(HHTP)₂/COOH-MWCNTs hybrid is developed for the simultaneous determination of these analytes. Benefiting from the unique π-π stacking and π-d conjugation characteristics of Cu₃(HHTP)₂, as well as the excellent coordination effect between COOH-MWCNTs and Cu²⁺ and the good dispersibility of carbon nanotubes themselves, the composite material exhibits more prominent surface activity, significantly boosting the exposure of active sites and accelerating the electron transfer kinetics at the electrode-electrolyte interface. On this basis, we constructed an electrochemical sensing platform for the simultaneous detection of DA and UA in human serum samples. The sensor show excellent performance with dual linear ranges of 0.5-15 and 15-80 μM for DA, and 1-200 and 200-350 μM for UA, achieving low LODs of 0.039 μM and 0.083 μM, respectively (S/N = 3). Furthermore, machine learning (ML) algorithms were employed to optimize electrochemical signal processing, enabling more accurate and robust analysis of complex data. The proposed approach achieved successful application in the simultaneous determination of DA and UA in human serum matrix samples.

Air self-charging aqueous zinc-ion batteries (AZIBs) have garnered significant attention for their integrated energy-harvesting and storage capabilities. However, their performance is often hindered by sluggish electrode reaction kinetics and restricted cation transport channels. Herein, an organic-inorganic composite cathode, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA)@VO₂, is constructed via a synergistic design strategy, in which NTCDA molecules uniformly coat and partially intercalate into the VO₂ layers, thereby optimizing electron transport and ion diffusion pathways. Compared with reported organic-inorganic composite cathodes that mainly rely on inorganic additives to improve conductivity or structural stability, NTCDA@VO₂ constructs an active organic-inorganic interface, in which VO₂ acts as an electron donor to regulate the electronic structure of NTCDA, while its layered framework enables the ordered distribution of NTCDA molecules. Benefiting from this structural synergy, the Zn//NTCDA@VO₂ battery exhibits an open-circuit voltage recovery to 1.21 V after 1 h of air exposure and delivers a high discharge capacity of 170.1 mAh g^-1 at 0.2 A g^-1. Experimental and theoretical analyses reveal that the carbonyl (C=O) groups serve as the main redox-active sites, participating in the cooperative insertion/extraction of Zn²⁺ and H⁺. Meanwhile, VO₂ acts as an electron donor when combined with NTCDA, promoting oxygen activation and reducing the oxygen reduction reaction (ORR) energy barrier from 0.91 to 0.39 eV, thereby accelerating charge transfer and ion migration. This work elucidates the electron-ion coupling mechanism at the organic-inorganic interface regulated by the inorganic framework, providing new insights for designing efficient air self-charging energy storage systems.

Lithium-rich manganese-based oxides (LRMO) are promising cathodes for high-energy-density lithium-metal batteries owing to their high operating voltage and large reversible capacity, but suffer from severe interfacial degradation at high voltages (≥4.8 V), primarily triggered by lattice oxygen release, electrolyte oxidation, and HF-induced corrosion. Herein, we design a multifunctional siloxane-based electrolyte additive, 1,3,5-tris(3,3,3-trifluoropropyl)methylcyclotrisiloxane (TFSO), to regulate these coupled degradation processes. TFSO simultaneously acts as an oxygen scavenger and HF trap, suppressing lattice oxygen reactivity while converting HF into stable SiF/SiO species. Meanwhile, it promotes the formation of robust, inorganic-rich CEI/SEI layers, enabling dual interfacial stabilization and uniform lithium deposition. In addition, TFSO reconstructs the Li⁺ solvation structure, reducing solvent participation in interfacial side reactions. As a result, the LRMO‖Li cell achieves 92.7% capacity retention after 300 cycles at 4.8 V, along with excellent wide-temperature performance (82.7% at 55 °C and 160 mAh g^-1 at 0 °C). This work highlights an effective electrolyte design strategy for mitigating oxygen-triggered interfacial degradation in high-voltage lithium metal batteries.

The amide I, II, and III spectra of the insulin dimer and ubiquitin were investigated using our recently developed localized, second-order vibrational quasi-degenerate perturbation theory (VQDPT2) combined with quantum mechanics/molecular mechanics calculations. By averaging over ten snapshots from molecular dynamics trajectories, we confirmed that the computed spectra converged to a sufficient degree. Although the method has intrinsic limitations due to the neglect of vibrational coupling between neighboring amide groups, we found that the method provides a useful basis for spectral analysis of these proteins. The analysis of the averaged amide I, II, and III bands revealed that, for both proteins, the amide II and III peak positions tend to be closely associated with the coil contribution, whereas the origin of the amide I maximum is more protein dependent. The calculated amide I and III frequencies of the coil structures showed good agreement with experimental values. The spectra of each secondary structure were further subdivided according to the type of hydrogen bonding within the secondary structure. For structurally constrained α-helix and β-sheet structures, hydrogen-bond-dependent amide I frequency shifts were found to correlate with changes in the amide dihedral angles (O=C-N-H). Localized VQDPT2 enables direct interpretation of amide band shifts associated with conformational changes and provides a deeper understanding of the structural origin responsible for these band shifts.