Skin wounds infected by Staphylococcus aureus (S.aureus) often face delayed healing and aggravated complications, especially with rising antibiotic resistance. To develop an alternative therapeutic strategy, we constructed a carrier-free self-assembled nanoparticle system (CA-BBR NPs) via molecular coordination between berberine (BBR) and caffeic acid (CA). The obtained CA-BBR NPs exhibit a significant synergistic antimicrobial effects against S.aureus, showing a minimum inhibitory concentration (MIC) of 0.025 µmol/mL. At twice the MIC (0.05 µmol/mL), the antibacterial activity reaches 92.09% ± 0.94%, considerably outperforming that of free BBR or CA. Mechanistic studies revealed that CA-BBR NPs physically disrupted bacterial membranes, as evidenced by biofilm destruction, increased cell membrane permeability, and altered membrane potential. These findings were corroborated by scanning electron microscopy (SEM), Bradford protein leakage analysis, and membrane potential measurements. The carrier-free design not only enhances antimicrobial potency but also reduces the risk of drug resistance. This work provides a promising nano-antibacterial platform for advanced wound dressing, with potential for treating resistant wound infections.

A rapid, sensitive, and convenient surface-enhanced Raman spectroscopy (SERS) substrate was developed using Fe₃O₄/C as the magnetic core and SiO₂-SH as the shell for the detection of aflatoxin B1 (AFB1). Ultra-small Fe₃O₄/C nanoparticles (NPs) with an average size of 6.30 ± 0.68 nm and excellent magnetic responsiveness were synthesized via a one-pot hydrothermal method, followed by the deposition of a uniform SiO₂ shell, followed by thiol-group functionalization to yield Fe₃O₄/C/SiO₂-SH. The magnetic core enables instantaneous separation of the substrate from solution after AFB1 adsorption, eliminating the need for centrifugation or filtration. When employed as a SERS substrate, significant enhancement of the characteristic Raman peak at 1482 cm⁻1 was observed across AFB1 concentrations of 0.1–10 μg/mL. Notably, the peak intensity at 10 μg/mL exceeded that of solid AFB1 powder. Comprehensive characterization (TEM, XRD, FTIR, XPS, and vibrating sample magnetometry) confirmed the core–shell structure, high crystallinity, and strong magnetic properties. The prepared Fe₃O₄/C/SiO₂-SH nanocomposite offers a low-cost, easily recyclable, and noble-metal-free platform, demonstrating strong potential for trace AFB1 monitoring in herbal medicines and food products.

Deep eutectic solvents (DESs), owing to their tunable physicochemical properties and environmental friendliness, have emerged as promising media for the extraction of natural products. In this study, a DES-functionalized magnetic core-shell sorbent (Fe3O4@C@PDA@DES) was successfully fabricated through a covalent grafting strategy and applied to magnetic solid-phase extraction (MSPE) coupled with High Performance Liquid Chromatography-Ultraviolet Detection (HPLC-UV) for the enrichment and determination of three flavonoids, namely quercetin, kaempferol, and isorhamnetin, in Ginkgo biloba leaves. The key parameters affecting extraction performance were systematically optimized. Under the optimized conditions, the proposed method exhibited excellent analytical performance, with good linearity in the range of 1–1000 ng mL−1 (R > 0.9995), low limits of detection (0.10–0.27 ng mL−1), and enrichment factors of 74–85. The sorbent showed high adsorption capacities toward quercetin, kaempferol, and isorhamnetin, reaching 335.67, 336.60, and 350.78 mg g−1, respectively. Good precision was achieved, with intra-day and inter-day relative standard deviations of 0.11–2.31% and 3.03–4.50%, respectively. The method was successfully applied to Ginkgo biloba leaf samples, yielding recoveries ranging from 90.07% to 109.05%. Furthermore, DFT calculations combined with IGMH and FT-IR analyses were employed to elucidate the adsorption mechanism. The results suggested that hydrogen-bonding and van der Waals interactions played major roles in the adsorption process. This work provides a rapid, sensitive, and environmentally friendly strategy for the enrichment and determination of trace bioactive compounds in complex plant matrices.

Nanozyme-driven chemotherapy kinetics therapy (CDT), in combination with traditional chemotherapy, is an effective approach to overcome the poor efficacy of a single chemotherapy drug in long-term treatment settings due to drug resistance. We developed a manganese-loaded boronic acid-functionalized bovine serum albumin, and loaded it onto Zeolitic imidazolate framework-8 (ZIF-8) to obtain a nanozyme PBM@ZIF-8 with excellent drug-loading capacity. The nanozyme PBM@ZIF-8 showed notable glutathione peroxidase-like and peroxidase-like activities, with high loading capacity of 10.34% with doxorubicin (DOX) and achieved pH- and glutathione (GSH)-responsive release, which is approximately three times the drug release amount in physiological conditions. Subsequently, DOX loaded PBM@ZIF-8 (PBM@ZIF-8-DOX) achieved active targeting of Hepatocellular carcinoma (HCC) by specifically binding to sialic acid receptors, accumulating extensively within HCC cells. Through catalytic reduction of intracellular GSH levels and increased reactive oxygen species levels, this nanozyme effectively kill HepG2 cells when combined with DOX chemotherapy. Additionally, we constructed an 3D HCC microsphere model to further validate the high targeting efficiency and HCC killing efficacy of the nanoparticles in vitro. In conclusion, PBM@ZIF-8 serves as an effective drug delivery platform, providing a promising strategy for multimodal treatment of HCC.

The biomedical applications of carbon dots (CDs) are frequently hindered by the intrinsic trade-off between functional recognition capability and biocompatibility. This challenge is particularly pronounced in the selective detection of tumor-associated biomarkers, such as adenosine diphosphate (ADP), where achieving high sensitivity without compromising biosafety remains a formidable hurdle. Herein, we report a natural-precursor engineering strategy that utilizes Cortex Fraxini to synthesize multifunctional carbon dots (CF-CDs). Under unified sensing conditions, CF-CDs exhibited a selective fluorescence quenching response toward ADP over structurally related nucleotides and representative biological interferents, with a good linear response in the concentration range of 0-15 mu M and a detection limit of 0.063 mu M. The recognition mechanism and cytocompatibility profile were systematically investigated using fluorescence competition assays, UV-vis absorption spectroscopy, timeresolved fluorescence decay analysis, zeta-potential measurements, theoretical calculations, and cellular viability evaluations. Both experimental and theoretical results indicate that the interaction between CF-CDs and ADP is predominantly driven by electrostatic interactions, further assisted by directional hydrogen bonding and weak van der Waals forces. The observed UV-vis absorption changes, together with the nearly unchanged fluorescence lifetime upon ADP addition, support a predominantly static quenching mechanism involving ground-state complex formation. Significantly, CF-CDs displayed favorable cytocompatibility across different cell lines, and live/dead staining confirmed that CF-CDs caused much less membrane damage than positively charged p-phenylenediamine-derived carbon dots (P-CDs). Spike-and-recovery experiments in diluted fetal bovine serum (FBS) further demonstrated the applicability of the CF-CDs probe in complex biological matrices. This work provides a high-performance fluorescent probe for nucleotide sensing and highlights the potential of biomassderived CDs to balance molecular recognition and biological safety.

Supramolecular deep eutectic solvents (SUPRADES) have are promising green extraction media for the sustainable extraction of bioactive compounds from plant materials. In this study, a combined strategy of SUPRADES with ultrasound-assisted extraction (UAE) was developed for the efficient extraction and enrichment of isoflavones from the root of Pueraria lobata. The extraction process was systematically optimized using single-factor experiments followed by Box-Behnken design (BBD) response surface methodology. The optimal SUPRADES system consisted of L‑proline and urea at a 1:2 molar ratio, supplemented with 5 wt% β‑cyclodextrin and 30 wt% water. Under these conditions, the yield of puerarin reached 70.4 ± 0.6 mg/g, which is 1.33‑ to 5.33‑fold higher than those obtained with conventional methods. The self‑assembled structure of the SUPRADES and its molecular‑level interaction mechanism with isoflavones were further elucidated by FT‑IR spectroscopy, ¹H NMR spectroscopy, and density functional theory (DFT) calculations. These results confirmed that the extraction process is synergistically driven by hydrogen bonding and β‑cyclodextrin‑mediated host-guest complexation. GAPI evaluation demonstrated the excellent environmental friendliness and sustainability of the established method. Collectively, this study provides a novel and efficient extraction strategy for isoflavones from Pueraria lobata root and offers a theoretical basis for green the extraction of natural products in traditional Chinese medicine.

Flavonoids in Scutellaria Radix (SR) exhibit significant pharmacological activities, yet conventional extraction methods often suffer from low efficiency and poor selectivity. Here, a green and effective strategy was developed using deep eutectic solvent (DES)-functionalized magnetic nanoparticles for selective flavonoid enrichment. Forty-eight DESs were screened, and levulinic acid/L-proline (2:1) was identified as the optimal system. The selected DES was employed to synthesize Fe3O4@SiO2@DES, which demonstrated high specificity and adsorption performance in magnetic solid-phase extraction. Under optimized conditions, adsorption efficiencies for four representative flavonoids ranged from 0.770 +/- 0.01 to 0.983 +/- 0.002, with desorption recoveries of 0.551 +/- 0.003 to 0.919 +/- 0.019. The method showed excellent linearity (R-2 >= 0.9998) and low limits of detection and quantification (0.01-0.35 mu g mL(-1) and 0.03-0.98 mu g mL(-1), respectively). Moreover, the adsorbent retained high adsorption efficiency after six reuse cycles, demonstrating stability and reusability. This work provides a sustainable and selective approach for flavonoid enrichment from SR and highlights the potential of DES-functionalized magnetic nanomaterials as an eco-friendly alternative to conventional organic solvent-based extraction.

The complementary fusogenic coiled-coil lipopeptides CPE and CPK have gained attention as mediators of drug delivery via membrane fusion for various therapeutic applications. However, the models used in these studies were mainly 2D cell cultures and animal models, leaving the in-site interaction and physiological effects of this lipopeptide system in vivo unclear. To address this, we constructed two 3D cell models in vitro, a mimicking lung organ (mLO) using 3D printed hydrogel cell scaffold and alveolar organoids (AOs) derived from mouse adult stem cells. These models were used to evaluate the lipopeptide modified membrane fused drug delivery system (MF-DDS) and showed the details of drug delivery in treating the acute lung injury (ALI) model based on the 3D models. Our results revealed that MF-DDS demonstrated superior drug delivery efficiency in mLO, particularly when cultured dynamically on a chip compared to a static U-shaped plate. Importantly, the MF-DDS demonstrated great biocompatibility with no significant changes in macrophage phenotype, inflammatory cytokine secretion, and lung barrier integrity on the mLO after the cell membrane fused with the artificial lipid membrane. In the lipopolysaccharide (LPS) induced injury model using mLO, the MF-DDS delivered naringin effectively, significantly reduced inflammatory factor secretion, macrophage polarization, and protected lung barrier disruption. Furthermore, the safety and effectiveness of MF-DDS were validated using AOs, underscoring its potential in treating ALI. These findings offer critical insights into the interactions between MF-DDS and organ systems, paving the way for faster and more precise evaluations of drug delivery strategies for disease treatment.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the head and neck. Due to low bioavailability and passive targetability of anticancer drugs show great limitations in cancer therapy, the treatment of OSCC faces major challenges. Folic acid (FA) targeting can deliver anticancer drugs efficiently into the tumor environment, further enhance the anti-cancer efficacy. Herein, the nanoplatform based on UiO-66 that encapsulated with an effective FA targeting ligands and the pH-responsive polyethylene glycol (PEG) layer for the targeted delivery of berberine (Ber) is constructed for fighting against OSCC. The FA modification and controlled pH-responsiveness enable the targeted delivery of UiO-66/PEG-FA, which promotes the release of Ber and increases the cumulative intracellular Ber concentration, which both promote consumption of glutathione (GSH) and induced generation of reactive oxygen species (ROS), further stimulate the secretion of inflammatory factors (TNF-αand IL-1β). A comprehensive evaluation ofin vitroandin vivoexperiments show that UiO-66@Ber/PEG-FA promote autophagy and apoptosis of tumor cells by regulating the expression of Beclin-1, ATG13, BAX and Bcl-2, and effectively inhibit tumor growth. Overall, UiO-66@Ber/PEG-FA exhibit superior pH-responsiveness and targeted therapeutic efficienciesin vitroand vivo, it can serve as an approach for OSCC therapy.

In this study, Fe3O4@C@Cu2O was synthesized using a solvothermal method. The morphology and structural characteristics of the material were systematically investigated through various characterization techniques, including TEM, XPS, FT-IR, DLS, and VSM. Its antibacterial efficacy was assessed through colony counting. Results showed that at a concentration of 0.5 mg/mL, Fe3O4@C@Cu2O nanoparticles with a copper atomic percentage of 2.42

In recent years, the diverse aglycones of Scutellaria baicalensis Georgi (SBG) have attracted growing interest owing to their broad pharmacological activities. As a crucial step in the research of these flavonoids, extraction critically influences their applicability in drug development and therapeutic performance. Efficient extraction strategies not only enhance yield and purity but also better preserve bioactivity, thereby helping to achieve expected effects in anti-inflammatory, antioxidant, and antitumor applications. However, current challenges include relatively low extraction efficiency of aglycones and unclear mechanisms against oral squamous cell carcinoma (OSCC). Therefore, this study aimed to optimize the extraction process of aglycones, establish content prediction models, and preliminarily investigate the anti-OSCC mechanisms. For extraction optimization, endogenous enzymatic hydrolysis (EEH) combined with ultrasound-assisted extraction (UAE) was applied, and parameters were systematically optimized using an integrated AHP-CRITIC weighting method coupled with Box-Behnken design-response surface methodology (BBD-RSM). For content prediction, infrared spectroscopy combined with chemometrics was employed to develop partial least squares regression (PLSR) models for four key aglycones: baicalein, wogonin, norwogonin, and oroxylin A. For pharmacological investigation, UPLC-Q-TOF/MS, network pharmacology, molecular docking, and experimental validation were integrated to explore the anti-cancer effects. The results demonstrated that under optimal extraction parameters-enzymatic hydrolysis at 55 °C for 10 h, liquid-solid (L/S) ratio of 40:1, ultrasonic time of 20 min, pH 5.4, and ultrasonic power of 350 W-the extraction efficiency was significantly improved. The established prediction models performed reliably, with Rpre > 0.77, RPD > 2.1, and a mean RSEP of 8.71 across all four aglycones. Moreover, baicalein, 4'-hydroxywogonin, norwogonin, skullcapflavone II, and luteolin were identified as core active components that induce apoptosis in CAL-27 cells by regulating targets including EGFR, BCL-2, and BAX, and modulating the PI3K-AKT signaling pathway, thereby exerting anti-OSCC effects. In conclusion, the optimized extraction process is efficient and reproducible, the content prediction models show good predictive ability, and the anti-OSCC mechanisms are supported by experimental evidence, providing valuable insights for the development of natural medicines.

With the widespread overuse of antibiotics, Staphylococcus aureus has developed multiple resistances to a variety of first-line antibiotics; therefore, it is imperative to explore novel antimicrobial strategies to solve the problem of resistance. Traditional Chinese medicines (TCM) are considered sources of chemicals with potential healing properties. In this study, berberine (BBR) and ferulic acid (FA) were used as raw materials to prepare nanoparticles with enhanced antibacterial activity by self-assembly technology. The study revealed that the self-assembly process involves non-covalent interactions. Minimum inhibitory concentration (MIC) of the FA-BBR NPs was 0.1 mu mol/mL, and the antibacterial rate of FA-BBR NPs with a concentration of 0.2 mu mol/mL against S. aureus was 94.56 +/- 0.57%, which was significantly higher than monomers. The Bradford protein concentration assay was used to analyze the leakage of cellular contents. Scanning electron microscopy (SEM) and the fluorescent probe DiSC3(5) revealed that the nanoparticles can affect the integrity and permeability of bacterial biofilm, which is a key factor contributing to their superior antibacterial activity.

A specific and sensitive fluorescent sensor was developed using nitrogen-doped carbon dots (N-CDs) as the signal source and aptamers as the specific recognition elements for detecting aflatoxin B1 (AFB1). The Fe3O4@C-GO aptamers (MGO-apt) first reacted with the fluorescent nitrogen-doped carbon dots conjugated with complementary DNA (N-CDs-cDNA) to form the MGO-apt-cDNA-N-CDs sensor complex, which emits a strong fluorescent signal for accurate detection. The MGO-apt-cDNA-N-CDs probe preferentially binds to the target analyte, specifically, the aptamer undergoes a significant conformational change upon binding with AFB1. When the double-stranded structure between the N-CDs-cDNA and the MGO-apt dissociates, it releases a portion of the fluorescent N-CDs-cDNA from the sensor complex, leading to a decrease in fluorescence intensity (FL). The FL of the released N-CDs-cDNA in the supernatant was monitored after magnetic separation to determine the amount of AFB1. Under optimal reaction conditions, the standard curve demonstrated a linear correlation between FL and AFB1 concentration in the range of 1-25 ng/mL, conclusively affirming the high selectivity of the sensor for AFB1. The sensor was used to detect AFB1 in lotus seed, achieving spiked recoveries ranging from 95.19 % to 104.75 %, with all relative standard deviations (RSDs) below 3 %. These results clearly demonstrate that the newly developed aptamer fluorescence sensor is highly effective for detecting AFB1.

To mitigate pollution caused by levofloxacin (LVF) in aquatic environments, a magnetic catalyst, CoFe2O4/CoFe@BC (CF@BC), was synthesized using loofah-derived biochar (BC) as a support, through coprecipitation followed by calcination at high temperatures. CF@BC was utilized for the degradation of LVF in aqueous solutions containing peroxymonosulfate (PMS), requiring no additional energy input. CF@BC demonstrates exceptional catalytic performance, even under acidic conditions, achieving a degradation rate of 98% within 4 min. Compared to pure CoFe2O4 nanoparticles (CF), CF@BC exhibits smaller particle sizes and improved dispersion properties, enhancing the exposure of reactive sites. The degradability of the CF@BC/PMS system is nearly three times greater than that of the CF/PMS system under identical conditions. Furthermore, the CF@BC/PMS system demonstrated effective degradation of LVF across a wide initial pH range (3 to 9) and maintained high degradation efficiency after three cycles. Both Co(II)/Co(III) and Fe(III)/Fe(II) are involved in the activation process of PMS, with SO4 center dot- and 1O(2) being the predominant species contributing to degradation. Additionally, two pathways for the degradation of LVF have been proposed. The CF@BC/PMS system developed in this study can be effectively applied to remediate water contaminated by LVF.

Rapid and convenient enrichment and detection of volatile cinnamaldehyde (Cin) from a common herbal medicine, cinnamon, was achieved through a reliable MSPE-HPLC-DAD approach. The magnetic porous carbon material (Carbon-Fe3C/lignin) used for MSPE was prepared as follows. First, the metal organic framework (MIL-101-NH2 (Fe)) was synthesized using the solvothermal method. Next, lignin was incorporated and carbonized in a nitrogen atmosphere. The resulting Carbon-Fe3C/lignin was then employed for the rapid extraction of Cin from cinnamon. Surprisingly, up to 88 % of the Cin in cinnamon were successfully extracted within 30 min. Carbon-Fe3C/lignin maintained a high adsorption capacity after multiple cycles. By inference, the doping with lignin enhanced the specific surface area of Carbon-Fe3C/lignin, improved the dispersion of Fe nanoparticles, and introduced more defects and oxygen-containing groups served as active adsorption sites. This adsorbent is expected to replace traditional extraction methods and provide a greener way to obtain volatile active ingredients from natural products.

Enzymes play a crucial role in the development and progression of various diseases, making them important targets for drug development. However, the stability issues associated with natural enzymes limit their broader application. Traditional methods for screening enzyme inhibitors from natural products are often time-consuming and labor-intensive. In this study, we designed and employed magnetic metal–organic frameworks (MOFs) to immobilize xanthine oxidase for the first time. By leveraging the porous structure and high specific surface area of MOFs, combined with the magnetic responsiveness of nanoparticles, we successfully developed a novel method for the efficient screening of potential enzyme inhibitors derived from natural products. By using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) as a cross-linking agent, we achieved efficient immobilization of xanthine oxidase and identified baicalin as a potential inhibitor from the extract of Scutellaria baicalensis. In addition, we confirmed the adsorption capacity of this method for hordenine, demonstrated the specific adsorption of allopurinol, and also performed in vitro activity validation for baicalein. We not only successfully prepared the immobilized enzyme but also showcased that this method can efficiently screen and isolate potential enzyme inhibitors from traditional Chinese medicine, which provides a rapid and efficient new strategy for identifying enzyme inhibitors in natural products. This innovative approach offers a fresh perspective on the application of botanical medicine and the pharmacological treatment of hyperuricemia, which has important theoretical and practical significance.

Efficiently eliminating metal ions from water remains a formidable challenge, primarily because of the intricate nature of impurities within the aqueous environment. In this study, magnetite nanoparticles encapsulated by an ultrathin carbon layer and graphene oxide (Fe3O4@C-GO) nanocomposite was further functionalized with polydopamine (PDA) to prepare Fe3O4@C-GO@PDA nanoadsorbent with improved adsorption capabilities for the effective elimination of metal ions from aqueous solutions. The Fe3O4@C-GO@PDA nanoadsorbent showed outstanding adsorption potential. Under the optimal the experimental conditions, the Fe3O4@C-GO@PDA nanoadsorbent effectively removed Zn(II), Cu(II), Pb(II), and Cd(II) ions from aqueous solutions at pH 6, with rates of 99.1 %, 97.7 %, 94.6 %, and 91.1 %, respectively. In comparison with Fe3O4@C-GO nanocomposite, the removal rate, removal capacity and removal equilibrium time of Pb on Fe3O4@C-GO@PDA nanoadsorbent all showed a great improvement. The adsorption of Pb(II) follows pseudo-second-order kinetics (R2 = 0.9993), indicating that chemical adsorption is the dominant mechanism. XPS and FTIR analyses revealed synergistic interactions between Pb(II) and surface functional groups (-NH2, C--O, -COOH). The slightly decrease in the the removal rate in the recovery and recyclability investigations after 5 cycles indicated that Fe3O4@C-GO@PDA nanoadsorbent can be repeatedly used for the removal of for Zn(II), Cu(II), Pb(II) and Cd(II) ions from water. As a result, the Fe3O4@C-GO@PDA nanoadsorbent not only realize the removal of Pb ions from water with efficient removal but also show potential application in the separation and purification of other common metal ions.

The application prospects of magnetic nanocomposites in cancer treatment and diagnosis are extensive, as they enable targeted drug delivery to tumors. Herein, a novel therapeutic strategy was proposed for oral squamous cell carcinoma (OSCC), in which polyethylene glycol-folic acid (FA-PEG) was modified on nanocomposites by combining Fe3O4 and layered double hydroxide (LDH) to obtain a drug carrier for the targeted delivery of the anticancer drug berberine (Ber). We have confirmed that FA-PEG/Fe3O4@LDH exhibited a high drug loading capacity for Ber and excellent biocompatibility. Moreover, it demonstrated remarkable pH-responsive drug release (Ber release of 3.87% and 53.77% within 48 h at pH 7.4 and 5.0, respectively). The cellular experiments demonstrated that FA-PEG/Fe3O4@LDH@Ber exhibited significant inhibition of cellular activity, while the targeted release of Ber effectively depleted the overexpressed GSH and promoted ROS generation, thereby facilitating oxidative stress and inducing mitochondrial dysfunction in CAL27 cells, thus promoting apoptosis of CAL27 cells. Therefore, FA-PEG/Fe3O4@LDH can be used as a potential pH-controlled release drug delivery system which has great significance for the targeted therapy of OSCC.

Designing adsorbents with high sensitivity, superior adsorption capacity, molecular specificity, and batch-to-batch reproducibility remains a significant challenge in separation science. For the first time, we synthesized a functionalized magnetic metal-organic framework (Fe₃O₄@SiO₂@MIL-101@CLCS), to adsorb magnoflorine, hesperidin, nitidine chloride, and chelerythrine from Toddalia asiatica (L.) Lam via electrostatic interactions and π-π stacking. In order to systematically analyze the target components, this study established a magnetic solid-phase extraction coupled with high-performance liquid chromatography-diode array detection (MSPE-HPLC-DAD) method, and comprehensively optimized the extraction and elution conditions. After optimization, the adsorption rates of Fe₃O₄@SiO₂@MIL-101@CLCS on the above four active ingredients were ranged from 52.52 % to 82.43 %, and the elution rates were all higher than 96.40 %. The adsorbent retained good adsorption capacity after 5 reuse cycles and had excellent recyclability. The method demonstrated excellent linearity (r² ≥ 0.999), with a limit of detection (LODs) of 0.17-0.92 μg/mL and a limit of quantification (LOQs) of 0.30-1.65 μg/mL, confirming high accuracy and precision. This approach not only enhances analytical efficiency in traditional Chinese medicine studies but also expands the potential of magnetic solid-phase extraction for natural product research.

A low cost-effective and simple synthesis method combining magnetic solid-phase extraction (MSPE) and high-pressure liquid chromatography was developed for the analysis of aristolochic acids I (AAI) in traditional Chinese medicine samples. A novel polydopamine (PDA) modified magnetic nanoparticles with one single carbon layer (Fe3O4@1C NPs) via one-pot hydrothermal approach was prepared and then successfully employed to extract AAI for the first time. Dopamine (DA) can form a PDA layer on Fe3O4@1C NPs surface through self-polymerization to form Fe3O4@1C@PDA. As a surface modifier of DA, PDA offered more adsorption sites to AAI due to π-π stacking, hydrogen bonding and electrostatic interactions. The parameters of MSPE were optimized by univariate and multivariate methods (Box-Behnken design) in detail. High degree of linearity was obtained in the range of 0.05-200.0 μg/mL. The limits of detection (S/N = 3) and quantification (S/N = 10) were 0.08 and 0.25 μg/mL, respectively. The recoveries of AAI in spiked Xiaoqinglong mixture samples were in the range of 86.7 to 108.5% with the relative standard deviation of less than 5.2%. Thus, a fast, convenient, sensitive and eco-friendly method was successfully proposed and became a promising approach for the determination of AAI in herbal plants or its preparation in the manufacturing procedure.