A Novel Enhanced-Fluorescent Probe Based on DHLA-Stabilized Red-Emitting Copper Nanoclusters for Methimazole Detection Via Aggregation-Induced Emission Effect.

Herein, an aqueous phase synthesis approach was presented for the fabrication of copper nanoclusters (Cu NCs) with aggregation-induced emission (AIE) property, utilizing lipoic acid and NaBH4 as ligands and reducing agent, respectively. The as-synthesized Cu NCs exhibit an average size of 3.0 ± 0.2 nm and demonstrate strong solid-state fluorescence upon excitation with UV light. However, when dissolved in water, no observable fluorescent emission is detected in the aqueous solution of Cu NCs. Remarkably, the addition of Methimazole induced a significant red fluorescence from the aqueous solution of Cu NCs. This unexpected phenomenon can be ascribed to the aggregation of negatively charged Cu NCs caused by electrostatic interaction with positively charged imidazole groups in Methimazole, resulting in enhanced fluorescence through AIE mechanism. Therefore, there exists an excellent linear correlation between the fluorescent intensities of Cu NCs aqueous solution and the concentration of Methimazole within a range of 0.1-1.5 mM with a low limit of detection of 82.2 µM. Importantly, the designed enhanced-fluorescent nanoprobe based on Cu NCs exhibits satisfactory performance in assaying commercially available Methimazole tablets, demonstrating its exceptional sensitivity, reliability, and accuracy.

Enhancing adversarial attacks with resize-invariant and logical ensemble.

In black-box scenarios, most transfer-based attacks usually improve the transferability of adversarial examples by optimizing the gradient calculation of the input image. Unfortunately, since the gradient information is only calculated and optimized for each pixel point in the image individually, the generated adversarial examples tend to overfit the local model and have poor transferability to the target model. To tackle the issue, we propose a resize-invariant method (RIM) and a logical ensemble transformation method (LETM) to enhance the transferability of adversarial examples. Specifically, RIM is inspired by the resize-invariant property of Deep Neural Networks (DNNs). The range of resizable pixel is first divided into multiple intervals, and then the input image is randomly resized and padded within each interval. Finally, LETM performs logical ensemble of multiple images after RIM transformation to calculate the final gradient update direction. The proposed method adequately considers the information of each pixel in the image and the surrounding pixels. The probability of duplication of image transformations is minimized and the overfitting effect of adversarial examples is effectively mitigated. Numerous experiments on the ImageNet dataset show that our approach outperforms other advanced methods and is capable of generating more transferable adversarial examples.

ZnS QDs Stabilized Concurrently with Glutathione and L-cysteine for Highly Sensitive Determining Adriamycin Based on the Fluorescence Enhancement Mechanism.

In this work, a facile and fast aqueous-phase synthetic method is proposed to prepare water-soluble ZnS quantum dots stabilized simultaneously with glutathione and L-cysteine (ZnS QDs-GSH/L-Cys). As-synthesized ZnS QDs-GSH/L-Cys were monodispersed spherical nanocrystals with a mean diameter of 5.0 ± 0.7 nm. Besides, the obtained ZnS QDs-GSH/L-Cys emitted more intensive blue fluorescence and exhibited an improved stability in aqueous solution compared with ZnS quantum dots merely stabilized with GSH (ZnS QDs-GSH). Interestingly, Adriamycin, a representative anticancer drug, was added into the solution of ZnS QDs-GSH/L-Cys, the blue fluorescence of ZnS QDs-GSH/L-Cys was greatly enhanced instead of being quenched, which indicated that ZnS QDs-GSH/L-Cys can be used as an enhanced-fluorescence nanoprobe for determining Adriamycin. The observed fluorescent enhancement could be attributed to the blocking of photoinduced electron transfer (PET) in ZnS QDs-GSH/L-Cys due to the electrostatic interaction between the -COO- groups on the surface of quantum dots and the -NH3+ groups in Adriamycin, followed by the coordination interaction among ZnS QDs-GSH/L-Cys and Adriamycin. The fluorescence intensity of ZnS QDs-GSH/L-Cys presented a good linear response with the concentration of Adriamycin ranging from 2.0 to 20 µg•mL-1. The proposed fluorescent nanoprobe exhibited an excellent sensitivity with the LOD of 0.1 µg•mL-1 and a good accuracy for detecting Adriamycin.

Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants.

Conversion of plastic wastes to fatty acids is an attractive means to supplement the sourcing of these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion to fatty acids with number-average molar masses of up to ~700 and 670 daltons, respectively. The process is applicable to municipal PE and PP wastes and their mixtures. Temperature-gradient thermolysis is the key to controllably degrading PE and PP into waxes and inhibiting the production of small molecules. The waxes are upcycled to fatty acids by oxidation over manganese stearate and subsequent processing. PP ꞵ-scission produces more olefin wax and yields higher acid-number fatty acids than does PE ꞵ-scission. We further convert the fatty acids to high-value, large-market-volume surfactants. Industrial-scale technoeconomic analysis suggests economic viability without the need for subsidies.

Synergistic Promotion of the Photocatalytic Preparation of Hydrogen Peroxide (H2 O2 ) from Oxygen by Benzoxazine and Si─O─Ti Bond.

Hydrogen peroxide (H2 O2 ) is considered one of the most important chemical products and has a promising future in photocatalytic preparation, which is green, pollution-free, and hardly consumes any non-renewable energy. This study involves the preparation of benzoxazine with Si─O bonds via the Mannich reaction, followed by co-hydrolysis to produce photocatalysts containing benzoxazine with Si─O─Ti bonds. In this study, a benzoxazine photocatalyst with Si─O─Ti bonds is synthesized and characterized using fourier transform infrared spectroscopy, nuclear magnetic resonance, and X-ray photoelectron spectroscopy. The size and elemental distribution of the nanoparticles are confirmed by transmission electron microscopy and scanning electron microscopy. The photocatalytic synthesis of H2 O2 is tested using the titanium salt detection method, and the rate is found to be 7.28 µmol h-1 . Additionally, the catalyst exhibits good hydrolysis resistance and could be reused multiple times. The use of benzoxazine with Si─O─Ti bonds presents a promising experimental and theoretical foundation for the industrial production of H2 O2 through photocatalytic synthesis.

miR-29c Suppresses the Malignant Phenotype of Hepatocellular Carcinoma Cells In Vitro by Mediating TPX2 Associated with Immune Infiltration.

BACKGROUND: miR-29-3p, an important tumor suppressor, with inhibitory effects in multiple cancers that have been studied. Its exact molecular function is in HCC, however, still not been explored clearly. The purpose of our study is to make certain how miR-29c-3p affects HCC through TPX2. MATERIALS AND METHODS: Expression profile data of miR-29c-3p and TPX2 were acquired and downloaded from the TCGA database, and the respective differential expression was verified by qPCR and immunohistochemistry. The StarBase and dual luciferase reporter confirmed TPX2 targeting miR-29c-3p. Their effects on the biological functions of Hep3B and HepG2 were investigated by cellular assays. RESULTS: miR-29-3p was found to be significantly down-regulated in HCC, and the miR-29-3p low expression group had a poor prognosis. Overexpression of miR-29-3p was detrimental to invasion and migration ability of HCC cells and promoted their apoptosis. We identified miR-29c-3p targeting TPX2 by predictive analysis. TPX2 was significantly upregulated in HCC, and patients with high TPX2 expression had a poor prognosis. TPX2 knockdown partially counteracted the promoting effect of miR-29-3p inhibition on hepatocellular carcinoma cells, and its effect on hepatocellular carcinoma cell biology was similar to miR-29c-3p overexpression. CONCLUSION: miR-29c, a key gene regulating HCC, is lowly expressed in HCC, its overexpression can remarkably inhibit the biological function of tumor cells. miR-29c can perform this function by regulating the expression of TPX2.

CAF-Released Exosomal miR-20a-5p Facilitates HCC Progression via the LIMA1-Mediated ß-Catenin Pathway.

Currently, exosomes derived from Cancer-associated fibroblast (CAF) have reportedly been involved in regulating hepatocellular carcinoma (HCC) tumour microenvironment (TME). LIM domain and actin binding 1 (LIMA1) is an actin-binding protein that is involved in controlling the biological behaviour and progression of specific solid tumours. We aimed to determine the effect of LIMA1 and exosome-associated miR-20a-5p in HCC development. LIMA1 and miR-20a-5p expression levels were examined by real-time quantitative PCR (qRT-PCR), western blotting or immunohistochemistry (IHC). Functional experiments, including Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) assays, colony formation assays, wound healing assays, and Transwell invasion assays, were performed to investigate the effect of LIMA1 and miR-20a-5p. A dual-luciferase reporter gene assay was performed to confirm the interaction of miR-20a-5p and LIMA1. Exosomes were characterised by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting. We noted that LIMA1 was downregulated in human HCC tissues and cells and remarkably correlated with overall survival (OS) and recurrence-free survival (RFS). LIMA1 overexpression suppressed HCC cell proliferation and metastasis in vitro and in vivo, while LIMA1 knockdown had the opposite effects. A mechanistic investigation showed that LIMA1 inhibited the Wnt/ß-catenin signalling pathway by binding to BMI1 and inducing its destabilisation. Additionally, we found that LIMA1 expression in HCC cells could be suppressed by transferring CAF-derived exosomes harbouring oncogenic miR-20a-5p. In summary, LIMA1 is a tumour suppressor that inhibits the Wnt/ß-catenin signalling pathway and is downregulated by CAF-derived exosomes carrying oncogenic miR-20a-5p in HCC.

Highly sensitive detection of polyborosiloxane (PBS) hydrolysis with mannitol using electrochemical methodology.

The complexation of polyhydric alcohols, such as mannitol, with boric acid ion promotes the ionization of boric acid. The hydrolysis performance of PBSs was determined using an electrochemical approach for the first time. Compared with the traditional methods, this approach includes the advantages of high sensitivity, continuity, and digitization.

PRDX6 knockout restrains the malignant progression of intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis. The bifunctional protein peroxiredoxin 6 (PRDX6), which has both calcium-independent phospholipase A2 (iPLA2) and glutathione peroxidase (GPx) activity, participates in the development of multiple tumors. However, the function and clinical significance of PRDX6 in ICC remain unclear. In this study, we characterized PRDX6 in both human ICC and thioacetamide (TAA)-induced rat ICC. We found PRDX6 was significantly increased in ICC tissues, compared with the peritumoral tissues, and PRDX6 expression level was positively correlated with the malignant phenotype in ICC patients. Furthermore, PRDX6 genetic knockout significantly inhibited the tumor progression in rats. By using RNA sequencing analysis, we found 127 upregulated genes and 321 downregulated genes after PRDX6 knockout. In addition, we noticed a significant repression in the Wnt7a/b cascade, which has been shown to play an important role in the occurrence of ICC. We confirmed that gene expressions in the Wnt7a/b cascade were inhibited in ICC tissues after PRDX6 knockout by using qRT-PCR and immunohistochemistry analysis. Collectively, our findings suggest that PRDX6 may promote ICC by regulating the Wnt7a/b pathway, which could be a novel therapeutic target for ICC.

Risk model of hepatocellular carcinoma based on cuproptosis-related genes.

Background: Owing to the heterogeneity displayed by hepatocellular carcinoma (HCC) and the complexity of tumor microenvironment (TME), it is noted that the long-term effectiveness of the cancer therapy poses a severe clinical challenge. Hence, it is essential to categorize and alter the treatment intervention decisions for these tumors. Materials and methods: "ConsensusClusterPlus" tool was used for developing a secure molecular classification system that was based on the cuproptosis-linked gene expression. Furthermore, all clinical properties, pathway characteristics, genomic changes, and immune characteristics of different cell types involved in the immune pathways were also assessed. Univariate Cox regression and the least absolute shrinkage and selection operator (Lasso) analyses were used for designing the prognostic risk model associated with cuproptosis. Results: Three cuproptosis-linked subtypes (clust1, clust2, and clust3) were detected. Out of these, Clust3 showed the worst prognosis, followed by clust2, while Clust1 showed the best prognosis. Three subtypes had significantly different enrichment in pathways related to Tricarboxylic Acid (TCA) cycle, cell cycle, and cell senescence (p < 0.01). The clust3 subtype with poor prognosis had a low "ImmuneScore" and low immune cell infiltration, and the three subtypes had significant differences in the antigen processing and presentation pathway of the macrophages. Clust1 had a low TIDE score and was sensitive to immunotherapy. Then, according to the prognosis-related genes of cuproptosis, a prognosis risk model related to cuproptosis was constructed, containing seven genes (KIF2C, PTTG1, CENPM, CDC20, CYP2C9, SFN, and CFHR3). "High" group had a higher TIDE score compared to the TIDE score value shown by the "Low" group, which benefited less from immunotherapy, whereas the "High" group patients were more sensitive to the conventional drugs. Finally, the prognosis risk model related to cuproptosis was combined with clinical pathological characteristics to further improve the prognostic model and survival prediction. Conclusion: Three new molecular subgroups based on cuproptosis-linked genes were revealed, and a cuproptosis-related prognostic risk model comprising seven genes was established in this study, which could assist in predicting the prognosis and identifying the patients benefit from immunotherapy.

Development of a Novel Model for Predicting Postoperative Short-Term Outcome in Patients with Hepatitis B-Related Acute-on-Chronic Liver Failure Undergoing Liver Transplantation.

BACKGROUND We aimed to create a novel predictive model through comparing the prognostic accuracy of the current mainstream scoring models in predicting the short-term outcome of patients with hepatitis B-related acute-on-chronic liver failure (HBACLF) undergoing liver transplantation (LT). MATERIAL AND METHODS Data on patients with HBACLF undergoing LT were retrospectively collected and analyzed. The area under the time-dependent receiver operating characteristic curve of 16 scoring models was calculated to evaluate their performance in predicting short-term survival after LT. Univariate analyses and LASSO regression were used to identify the independent variables, which were further selected by Cox stepwise regression. RESULTS A total of 135 patients were enrolled. Among the 16 scoring models, MELD-Na performed the best in predicting 3-month mortality after LT, with an AUC of 0.716. LASSO regression analysis revealed that only the MELD-Na was confirmed as an independent predictor (HR 1.0481, 95% C.I [1.0136, 1.0838], P<0.05). Cox stepwise regression identified 4 variables - MELD-Na, sex, systemic infection, and placement of T-tube during operation - which were used to construct a novel prognostic model with a C-index of 0.844 and a Brier score of 0.131 after internal validation and a C-index of 0.824 (95% C.I [0.658, 0.989]) and a Brier score of 0.119 in the external validation cohort at 3 months. CONCLUSIONS Compared with other scoring models, MELD-Na was an independent factor in predicting short-term outcome after LT. The constructed novel predictive model could exert clinical benefits on early prognostic assessment and case selection.

The Benefits of Radical Treatments with Synchronous Splenectomy for Patients with Hepatocellular Carcinoma and Portal Hypertension.

Background: The survival benefits of radical treatment (resection or radiofrequency ablation) combined with splenectomy for primary hepatocellular carcinoma (HCC) in patients with liver-cirrhosis-associated portal hypertension (PH) remain to be clarified. Methods: 96 patients undertaking HCC radical treatment combined with splenectomy (HS group) were retrospectively analyzed, 48 of whom belonged to HCC stage T1 (HSS group). Another 42 patients at stage T1 with PH who received hepatectomy (or radiofrequency ablation) alone (HA group) during the same period served as the control group. Recurrence-free survival (RFS) and overall survival (OS) were compared at each time point between the HSS and HA group. The risk factors affecting early RFS and OS were confirmed through COX multivariate analysis. Results: The median RFS was 22.3 months and the mean median OS was 46 months in the HS group. As such, 1-year, 2-year, 3-year, and 5-year RFS rates in the HSS and HA group were 95% and 81% (p = 0.041), 81% and 67% (p = 0.05), 64% and 62% (p = 1.00), and 29% and 45% (p = 0.10), respectively. Further, 1-year, 3-year, and 5-year OS rates in the HSS and HA group were 98% and 98% (p = 1.00), 79% and 88% (p = 0.50), and 60% and 64% (p = 0.61), respectively. Cox multivariate analysis showed that preoperative irregular anti-viral therapy, Child-Pugh grade B liver function, vascular invasion, and microvascular invasion (MVI) were independent risk factors for early postoperative RFS (within 2 years), and preoperative irregular anti-viral therapy and vascular invasion were independent risk factors for 5-year OS. Conclusions: Radical treatment of HCC combined with synchronous splenectomy, especially applicable to patients with Child-Pugh grade A liver function, can significantly improve early postoperative RFS in patients with stage T1 HCC and liver-cirrhosis-associated portal hypertension, but fail to improve OS.

Dissecting the Molecular Regulation of Natural Variation in Growth and Senescence of Two Eutrema salsugineum Ecotypes.

Salt cress (Eutrema salsugineum, aka Thellungiella salsuginea) is an extremophile and a close relative of Arabidopsis thaliana. To understand the mechanism of selection of complex traits under natural variation, we analyzed the physiological and proteomic differences between Shandong (SD) and Xinjiang (XJ) ecotypes. The SD ecotype has dark green leaves, short and flat leaves, and more conspicuous taproots, and the XJ ecotype had greater biomass and showed clear signs of senescence or leaf shedding with age. After 2-DE separation and ESI-MS/MS identification, between 25 and 28 differentially expressed protein spots were identified in shoots and roots, respectively. The proteins identified in shoots are mainly involved in cellular metabolic processes, stress responses, responses to abiotic stimuli, and aging responses, while those identified in roots are mainly involved in small-molecule metabolic processes, oxidation-reduction processes, and responses to abiotic stimuli. Our data revealed the evolutionary differences at the protein level between these two ecotypes. Namely, in the evolution of salt tolerance, the SD ecotype highly expressed some stress-related proteins to structurally adapt to the high salt environment in the Yellow River Delta, whereas the XJ ecotype utilizes the specialized energy metabolism to support this evolution of the short-lived xerophytes in the Xinjiang region.

Transcriptomic Profiling Provides Molecular Insights Into Hydrogen Peroxide-Enhanced Arabidopsis Growth and Its Salt Tolerance.

Salt stress is an important environmental factor limiting plant growth and crop production. Plant adaptation to salt stress can be improved by chemical pretreatment. This study aims to identify whether hydrogen peroxide (H2O2) pretreatment of seedlings affects the stress tolerance of Arabidopsis thaliana seedlings. The results show that pretreatment with H2O2 at appropriate concentrations enhances the salt tolerance ability of Arabidopsis seedlings, as revealed by lower Na+ levels, greater K+ levels, and improved K+/Na+ ratios in leaves. Furthermore, H2O2 pretreatment improves the membrane properties by reducing the relative membrane permeability (RMP) and malonaldehyde (MDA) content in addition to improving the activities of antioxidant enzymes, including superoxide dismutase, and glutathione peroxidase. Our transcription data show that exogenous H2O2 pretreatment leads to the induced expression of cell cycle, redox regulation, and cell wall organization-related genes in Arabidopsis, which may accelerate cell proliferation, enhance tolerance to osmotic stress, maintain the redox balance, and remodel the cell walls of plants in subsequent high-salt environments.

Novel composite nanomaterials based on magnetic molecularly imprinted polymers for selective extraction and determination of rutin in fruit juice.

In this work, with the attempt to further improve the selectivity, magnetism and loading proportion of existing adsorbents, a novel composite (MGO/MHNTs@MIPs) was synthesized by electrostatically combining molecularly imprinted polymer based on the surface of magnetic halloysite nanotubes (MHNTs@MIPs) with magnetic graphene oxide (MGO). Then some characterizations were done to prove its successful synthesis. Besides, the bonding experiment showed that it possessed a loading capacity of up to 132 mg·g-1, and the adsorption behavior of MGO/MHNTs@MIPs was elucidated by Langmuir isotherm model and Pseudo-second order model. By comparing its adsorption capacity to analogues, we concluded that the MGO/MHNTs@MIPs with the MHNTs@MIPs as basic elements exhibited higher selectivity (imprinting factor = 2.25) than that of MGO/MHNTs@NIPs based on MHNTs@NIPs for template rutin. Furthermore, a series of solid phase extraction conditions were optimized, and then the materials were used for the extraction and detection of rutin in fruit juice under the optimal conditions.

Metal-Organic Frameworks Encapsulating Carbon Dots Enable Fast Speciation of Mono- and Divalent Copper.

Copper is an essential element to play significant roles in human health associated to the strong redox properties of Cu(I) and Cu(II). The concurrent monitoring of copper species in biological matrixes is highly desired. Herein, a dual-channel fluorescence nanoprobe was designed for the speciation of mono- and divalent copper by conjugating carbon dots (CDs) with Eu-based metal-organic frameworks (Eu-MOFs). The obtained Eu-MOFs@CD nanoprobe exhibits fluorescence at λex/λem = 380/454 nm from CDs and λex/λem = 275/615 nm from Eu-MOFs. Bathocuproine disulfonate (BCS) specifically chelates Cu+ to produce a BCS-Cu+ adduct with absorption at 480 nm, which quenches the fluorescence of CDs at 454 nm due to the inner filter effect. On the other hand, Cu2+ quenches the fluorescence of Eu-MOFs due to the replacement of Eu3+ by Cu2+. Thus, Eu-MOFs@CDs enable extremely fast detection of Cu+ and Cu2+ within 1 min. Furthermore, the nanoprobe is demonstrated by monitoring the variation of Cu+ and Cu2+ in the degradation process of copper nanoparticles and Cu-based MOFs.

A panel of platelet-associated circulating long non-coding RNAs as potential biomarkers for colorectal cancer.

Evidence has suggested the potential of tumor-educated platelets as a biomarker trove for cancer diagnostics, but the difficulty in isolation limits its application. Since most of the circulating RNAs are derived from platelets, the change of RNA profile in platelets may lead to altered RNA expression in serum. Here, we identified a panel of platelet-associated long non-coding RNAs (lncRNAs) and evaluated its diagnostic capacity in serum of colorectal cancer (CRC) patients. Four lncRNAs, LNCAROD, SNHG20, LINC00534, and TSPOAP-AS1, were upregulated in both platelets and serum of CRC patients. A binary logistic model derived from them has validated area under roc curve of 0.78 indicating great performance. Furthermore, the expression levels of LNCAROD and TSPOAP-AS1 were correlated with cancer staging and tumor location. Together, our results add novel lncRNA biomarkers to the list of blood tests for CRC diagnostics and provide molecular evidence for the cross-talk between CRC platelets and serum.

Learnable Heterogeneous Convolution: Learning both topology and strength.

Existing convolution techniques in artificial neural networks suffer from huge computation complexity, while the biological neural network works in a much more powerful yet efficient way. Inspired by the biological plasticity of dendritic topology and synaptic strength, our method, Learnable Heterogeneous Convolution, realizes joint learning of kernel shape and weights, which unifies existing handcrafted convolution techniques in a data-driven way. A model based on our method can converge with structural sparse weights and then be accelerated by devices of high parallelism. In the experiments, our method either reduces VGG16/19 and ResNet34/50 computation by nearly 5× on CIFAR10 and 2× on ImageNet without harming the performance, where the weights are compressed by 10× and 4× respectively; or improves the accuracy by up to 1.0% on CIFAR10 and 0.5% on ImageNet with slightly higher efficiency. The code will be available on www.github.com/Genera1Z/LearnableHeterogeneousConvolution.

Regulation of Plant Responses to Salt Stress.

Salt stress is a major environmental stress that affects plant growth and development. Plants are sessile and thus have to develop suitable mechanisms to adapt to high-salt environments. Salt stress increases the intracellular osmotic pressure and can cause the accumulation of sodium to toxic levels. Thus, in response to salt stress signals, plants adapt via various mechanisms, including regulating ion homeostasis, activating the osmotic stress pathway, mediating plant hormone signaling, and regulating cytoskeleton dynamics and the cell wall composition. Unraveling the mechanisms underlying these physiological and biochemical responses to salt stress could provide valuable strategies to improve agricultural crop yields. In this review, we summarize recent developments in our understanding of the regulation of plant salt stress.

Reduction of nitroarenes by magnetically recoverable nitroreductase immobilized on Fe3O4 nanoparticles.

Enzymes as catalysts have attracted significant attention due to their excellent specificity and incomparable efficiency, but their practical application is limited because these catalysts are difficult to separate and recover. A magnetically recoverable biocatalyst has been effectively prepared through the immobilization of a nitroreductase (oxygen-insensitive, purified from Enterobacter cloacae) onto the Fe3O4 nanoparticles. The magnetic nanoparticles (MNPs) were synthesized by a coprecipitation method in an aqueous system. The surfaces of the MNPs were modified with sodium silicate and chloroacetic acid (CAA). Using 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) through a covalent binding, nitroreductase was loaded onto the modified magnetic carriers through covalent coupling, and thus, a magnetically recoverable biocatalyst was prepared. The free and immobilized nitroreductase activity was also investigated by the reduction of p-nitrobenzonitrile using nicotinamide adenine dinucleotide phosphate (NAPDH) as a cofactor. The activity of the immobilized enzyme was able to maintain 83.23% of that of the free enzyme. The prepared enzyme can easily reduce substituted nitrobenzene to substituted aniline at room temperature and atmospheric pressure, and the yield is up to 60.9%. Most importantly, the loaded nitroreductase carriers can be easily separated and recycled from the reaction system using an externally applied magnetic field. The magnetically recoverable biocatalyst can be recycled and reused 7 times while maintaining high activities and the activity of the magnetic catalyst can be maintained at more than 85.0% of that of the previous cycle. This research solves the recovery problem encountered in industrial applications of biocatalysts and presents a clean and green method of preparing substituted aniline.