Fluorescent and Colorimetric Dual-Readout Immunochromatographic Assay for the Detection of Phenamacril Residues in Agricultural Products.

The fungicide phenamacril has been employed to manage Fusarium and mycotoxins in crops, leading to persistent residues in the environment and plants. Detecting phenamacril is pivotal for ensuring environmental and food safety. In this study, haptens and artificial antigens were synthesized to produce antiphenamacril monoclonal antibodies (mAbs). Additionally, gold nanoparticles coated with a polydopamine shell were synthesized and conjugated with mAbs, inducing fluorescence quenching in quantum dots. Moreover, a dual-readout immunochromatographic assay that combines the positive signal from fluorescence with the negative signal from colorimetry was developed to enable sensitive and precise detection of phenamacril within 10 min, achieving detection limits of 5 ng/mL. The method's reliability was affirmed by using spiked wheat flour samples, achieving a limit of quantitation of 0.05 mg/kg. This analytical platform demonstrates high sensitivity, outstanding accuracy, and robust tolerance to matrix effects, making it suitable for the rapid, onsite, quantitative screening of phenamacril residues.

A Novel Magnetic ß-Cyclodextrin-Modified Graphene Oxide and Chitosan Composite as an Adsorbent for Trace Extraction of Four Bisphenol Pollutants from Environmental Water Samples and Food Samples.

In this study, a novel functionalized magnetic composite (MNCGC) for magnetic solid-phase extraction of bisphenols from environmental and food samples was developed, featuring a multistep synthesis with Fe3O4, chitosan, graphene oxide, and ß-cyclodextrin, crosslinked by glutaraldehyde. Characterization confirmed its advantageous morphology, intact crystal structure of the magnetic core, specific surface area, and magnetization, enabling efficient adsorption and separation via an external magnetic field. The optimized MSPE-HPLC-FLD method demonstrated excellent sensitivity, linearity, and recovery rates exceeding 80% for bisphenol pollutants, validating the method's effectiveness in enriching and detecting trace levels of bisphenols in complex matrices. This approach offers a new avenue for analyzing multiple bisphenol residues, with successful application to environmental water and food samples, showing high recovery rates.

Colorimetric and Reverse Fluorescence Dual-Signal Readout Immunochromatographic Assay for the Sensitive Determination of Sibutramine.

Later flow immunochromatographic assay has been widely used in clinical, environmental, and other diagnostic applications owing to its high sensitivity and throughput. However, most immunoassays operate in the "turn-off" mode for detecting targets of low molecular weight. The signal intensity decreases as the analyte concentration increases, which poses a challenge for achieving ultrasensitive detection at low concentrations and is counterintuitive to new users. In this work, a fluorometric immunochromatographic assay (FICA) is developed to simultaneously read "turn-on" fluorescent and "turn-off" colorimetric signals, where ZnCdSe/ZnS quantum dots act as fluorescence donors and gold nanoparticles (AuNPs) act as quenchers. The fluorescent signal (excitation/emission wavelengths of 365/525 nm) is positively correlated with analytes' concentration. Taking sibutramine (SBT) as the analysis target, the visual limit of detection for SBT reached 3.9 ng/mL, and the limit of Quantitation was 5.0 ng/mg in spiked samples. The developed FICA achieves a high sensitivity in SBT detection, which is much lower than that of the colloidal gold-based immunochromatographic assay. This dual-function detection mode has great potential to be used as a rapid on-site semiquantitative method, providing an alternative mode for the determination of low levels of target analytes.

ANXA3-Rich Exosomes Derived from Tumor-Associated Macrophages Regulate Ferroptosis and Lymphatic Metastasis of Laryngeal Squamous Cell Carcinoma.

Tumor-associated macrophages (TAM) induce immunosuppression in laryngeal squamous cell carcinoma (LSCC). The interaction between LSCC cells and TAMs affects the progression of laryngeal cancer through exosomes, but the underlying molecular mechanism remains unclear. Proteomics analysis of TAMs isolated from human laryngeal tumor tissues obtained from patients with confirmed lymphatic metastasis revealed an upregulation of annexin A3 (ANXA3). In TAMs, ANXA3 promoted macrophages to polarize to an M2-like phenotype by activating the AKT-GSK3ß-ß-catenin pathway. In addition, ANXA3-rich exosomes derived from TAMs inhibited ferroptosis in laryngeal cancer cells through an ATF2-CHAC1 axis, and this process was associated with lymphatic metastasis. Mechanistically, ANXA3 in exosomes inhibited the ubiquitination of ATF2, whereas ATF2 acted as a transcription factor to regulate the expression of CHAC1, thus inhibiting ferroptosis in LSCC cells. These data indicate that abnormal ANXA3 expression can drive TAM reprogramming and promote an immunosuppressive microenvironment in LSCC. Meanwhile, ANXA3-rich exosomes inhibit ferroptosis of LSCC cells and promote lymphatic metastasis, thus promoting tumor progression.

Competitive ratiometric fluorescent lateral flow immunoassay based on dual emission signal for sensitive detection of chlorothalonil.

In this study, we develop a competitive ratiometric fluorescent lateral flow immunoassay (CRF-LFIA) based on dual emission fluorescence signal, which has great advantage in visual and quantitative detection of Chlorothalonil (CTN). Red-emitted fluorescent magnetic nanobeads (FMNBs) and green-emitted aggregation-induced emission fluorescent microsphere (AIEFM) are synthesized and conjugated to antibodies and antigens respectively, resulting in competitive binding with the analyte. The ratiometric fluorescence signal which comes from the overlap of these two fluorescence emissions. FMNBs probes also provide immunomagnetic separation (IMS) to enrich the analysts and resist complex matrix effects. This strip generates a visually discernible yellow-to-green fluorescence color change in the presence of CTN (2 ng/mL), which could be incisively observed by naked eye. Moreover, the limit of detection (LOD) reached 0.152 ng/mL by measurement of color (Red-Green-Blue, RGB) signals. Method validation shows a good correlation between CRF-LFIA and LC-MS/MS.

Adsorption behavior and interaction mechanism of microplastics with typical hydrophilic pharmaceuticals and personal care products.

Microplastics (MPs) and pharmaceuticals and personal care products (PPCPs) are two types of emerging contaminants widely present in the global aquatic ecosystem. The ecological risks associated with the coexistence of these two contaminants have garnered increasing attention from researchers. In this study, we selected 15 typical hydrophilic PPCPs, including Sulfacetamide (SA), Thiamphenicol, Florfenicol, Chloramphenicol (CHL), Ampicillin, Cephalexin, Ofloxacin, Fluorouracil, Phenytoin, Theophylline, Cimetidine, Methylparaben, Diethyltoluamide, Benzophenone-2 (BP-2), and Benzophenone-4, as adsorbates. We evaluated the adsorption potential of five traditional plastics (TPs), namely Polyamide 6 (PA6), Polystyrene (PS), Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), and Polyurethane (TPU), as well as three biodegradable plastics (BDPs), including Polylactic acid (PLA), Polybutylene succinate (PBS), and Poly (ε-caprolactone) (PCL), for these adsorbates. Out of the 120 combinations of MPs and PPCPs tested, only 24 exhibited significant adsorption behavior. Notably, the adsorption performance of the three BDPs was stronger than that of the three typical TPs (PS, PET, and PVC). Based on their adsorption potential, PA6, BDPs, phenytoin, and BP-2 were identified as potential sources of high ecological risk. To further explore the adsorption mechanism, we investigated the adsorption behaviors of SA, BP-2, and CHL on PA6. The conclusions were as follows: SA, BP-2, and CHL all reached adsorption equilibrium within 24 h, with the partition coefficient (Kd) following this order: BP-2 (8.051) â‰« SA (0.052) > CHL (0.018). The primary forces of adsorption were electrostatic interactions, intermolecular hydrogen bonding, and hydrophobic interaction, respectively. Additionally, weak electrostatic effects were observed in the adsorption of CHL and BP-2. The effects of pH, ionic strength, and fulvic acid on adsorption capacity varied. These results highlight a complex adsorption mechanism between MPs and hydrophilic contaminants in the aquatic environment. This study provides a basis for further evaluating the ecological risks of MPs and PPCPs combined pollution.

Highly resistant and sensitive colorimetric immunochromatographic assay for sibutramine (SBT) illegally adulterated into diet food based on PDA/AuNP labelling.

A gold nanoparticle (AuNP) based immunochromatographic assay strip is a valuable tool for monitoring chemicals in foods. However, the sensitive ICA strip for SBT is rarely reported due to the fact that monoclonal antibodies (mAbs) against SBT with high affinity are commercially unavailable. Herein, a monoclonal antibody against SBT was prepared through a designed hapten with a carboxyl end-capped space arm. The obtained mAb showed high affinity for SBT and N-desmethylsibutramine, a metabolite of SBT. Furthermore, a series of core-shell NPs, polydopamine (PDA) coated AuNPs (PDA/AuNPs) with controlled shell thickness and packing density were synthesized. The obtained PDA/AuNP-mAb conjugate demonstrated high tolerance to salt and good stability in a wide pH range, which is beneficial for improving the matrix interference common in ICA. As a result, PDA/AuNP-based ICA could quantify SBT in the range of 3.39-69.60 ng mL-1 with a limit of detection (LOD) of 0.98 ng mL-1. This novel ICA improved the sensitivity of the traditional AuNP-based ICA by nearly 12 times. Method validation was conducted with spiked samples of slimming food and human serum and compared with HPLC-MS/MS. Consistent results indicated that high sensitivity, accuracy, and reliability of the PDA/AuNP-based ICA approach were achieved. To the best of our knowledge, this study reported the most sensitive immunoassay for SBT thus far.

Targeting reactive oxygen species and fat acid oxidation for the modulation of tumor-associated macrophages: a narrative review.

Tumor-associated macrophages (TAMs) are significant immunocytes infiltrating the tumor microenvironment(TME). Recent research has shown that TAMs exhibit diversity in terms of their phenotype, function, time, and spatial distribution, which allows for further classification of TAM subtypes. The metabolic efficiency of fatty acid oxidation (FAO) varies among TAM subtypes. FAO is closely linked to the production of reactive oxygen species (ROS), which play a role in processes such as oxidative stress. Current evidence demonstrates that FAO and ROS can influence TAMs' recruitment, polarization, and phagocytosis ability either individually or in combination, thereby impacting tumor progression. But the specific mechanisms associated with these relationships still require further investigation. We will review the current status of research on the relationship between TAMs and tumor development from three aspects: ROS and TAMs, FAO and TAMs, and the interconnectedness of FAO, ROS, and TAMs.

Uncovering the Nutritive Profiles of Adult Male Chinese Mitten Crab (E. sinensis) Harvested from the Pond and Natural Water Area of Qin Lake Based on Metabolomics.

E. sinensis, normally harvested in October and November, is an economic aquatic product in China. Pond culture has been widely applied for the production of E. sinensis, wherein a stable food supply for crabs is provided. In order to improve the nutritional quality of E. sinensis products, this study evaluated the effect of the local pond culture on the nutritive profiles of E. sinensis and screened out the best harvest time for the nutrient-rich crabs, thereby guiding the local crab industry to improve its aquaculture mode and harvest strategy. The results indicated that pond culture enhanced the levels of protein, amino acids, and specific organic acid derivatives, and reduced the levels of peptides and polyunsaturated fatty acids (PUFAs). Compared with E. sinensis harvested in October, peptide levels were significantly increased, whereas sugar, phenolic acid, and nucleotide levels were decreased in those harvested in November. Overall, the study revealed that the nutritive profile of the pond-reared E. sinensis was significantly modulated by a high-protein diet, thus lacking the diversity of metabolites. Additionally, October could be more appropriate for harvesting E. sinensis than November.

DACH1 regulates macrophage activation and tumour progression in hypopharyngeal squamous cell carcinoma.

Dachshund family transcription factor 1 (DACH1) has been shown to exhibit a tumour-suppressive role in a number of human cancers. However, the role of DACH1 in hypopharyngeal squamous cell carcinoma (HPSCC) and its function in the tumour microenvironment (TME) are still not clear. Crosstalk between cancer cells and tumour-associated macrophages (TAMs) mediates tumour progression in HPSCC. The expression of DACH1, CD86 and CD163 was detected in 71 matched HPSCC-non-cancerous tissue pairs using quantitative real-time polymerase chain reaction and IHC analysis. Cell proliferation, migration and invasion were monitored by colony formation, Transwell and EdU incorporation assays. ChIP-qPCR and dual-luciferase reporter assays were applied to verify the targeting relationships between DACH1 and IGF-1. Stably transfected HPSCC cells were co-cultured with MΦ macrophages to assess macrophage polarization and secretory signals. DACH1 was decreased in HPSCC tissues and was indicative of a poor prognosis for HPSCC patients. Decreased DACH1 expression in HPSCC was associated with fewer CD86+ TAMs and more CD163+ TAMs. Knockdown of DACH1 inhibited the proliferation, migration and invasion of FaDu cells via Akt/NF-κB/MMP2/9 signalling. Additionally, DACH1 was found to directly bind to the promoter region of IGF-1 to downregulate the secretion of IGF-1, which inhibited TAMs polarization through the IGF-1R/JAK1/STAT3 axis. Furthermore, in nude mice, the effects of DACH1 inhibition on tumour progression and M2-like TAMs polarization were confirmed. These findings suggest that IGF-1 is a critical downstream effector of DACH1 that suppresses cell migration and invasion and inhibits TAMs polarization. DACH1 could be a therapeutic target and prognostic marker for HPSCC.

An Integrated Approach to Improve the Assay Performance of Quantum Dot-Based Lateral Flow Immunoassays by Using Silver Deposition.

Traditional quantum dot-based lateral flow immunoassay (QD-LFIA) is limited to signal loss in part by the blinking, photobleaching and oxidative quenching of QD probes. Inspired by the good application of silver deposition on QD surfaces in tissue imaging, and in the context of improving the assay performance without compromising the simplicity and practicality, we report that introducing the QD-silver combination to the LFIA system, has the advantages of accuracy improvement, signal enhancement and user friendliness promotion, but maintains the cost-effective property and commercial accessibility of QD-LFIA. The effect was shown by using CdSe/ZnS QD-LFIA coupled with anti-sodium pentachlorophenate antibody, which provided a 4-fold improvement in the signal, a 2.5-fold improvement in the detection limit and a zero false-negative rate for sodium pentachlorophenate analysis in chicken samples. The proposed LFIA integrates the possibilities of colorimetric and fluorometric detection with different detection limits (fluorometric at 10 ng/mL and colorimetric at 4 ng/mL) and with acceptable detection times (fluorometric at 12 min and colorimetric at 27 min). The current results indicate that this QD-silver combined LFIA is complementary to conventional fluorescence LFIA and could be an inexpensive, versatile, and sensitive alternative.

Trace Immunosensing of Multiple Neonicotinoid Insecticides by a Novel Broad-Specific Antibody Obtained from a Rational Screening Strategy.

Residues of neonicotinoid pesticides have potential risks to food, environmental and biological safety. In this study, the hapten toward imidacloprid was adopted to gain antibodies. After molecular modeling, the electrostatic potentials of eight commonly-used neonicotinoid pesticides were individually calculated to analyze the structural similarity. Two representative compounds (imidacloprid and acetamiprid) with moderate similarity were rationally selected for hybridoma screening. Using this strategy, four clones of broad-specific monoclonal antibodies (mAbs) against multiple neonicotinoids were obtained, and the clone 6F11 exhibited the broadest spectrum to six neonicotinoid pesticides and two metabolites, with half-maximal inhibitory concentrations (IC50) ranging from 0.20 to 5.92 ng/mL. Then, the novel antibody gene was sequenced and successfully expressed in full-length IgG form using mammalian cells. Based on the sensitive recombinant antibody, a gold lateral-flow immunosensing strip assay was developed and it was qualified for rapid detection of imidacloprid, clothianidin or imidaclothiz residues in food samples.

Antimicrobial coating strategy to prevent orthopaedic device-related infections: recent advances and future perspectives.

The rapid development of multidrug-resistant (MDR) bacteria and biofilm-related infections (BRIs) has urgently called for new strategies to combat severe orthopaedic device-related infections (ODRIs). Antimicrobial coating has emerged as a promising strategy in halting the incidence of ODRIs and treating ODRIs in long term. With the advancement of material science and biotechnology, numerous antimicrobial coatings have been reported in literature, showing superior antimicrobial and osteogenic functions. This review has specifically discussed the currently developed antimicrobial coatings in the perspective of drug release from the coating system, focusing on their realization of controlled and on demand antimicrobial agents release, as well as multi-functionality. Acknowledging the multidisciplinary nature of antimicrobial coating, the conceptual design, the deposition method and the therapeutic effect of the antimicrobial coatings have been described in detail and discussed critically. Particularly, the challenges and opportunities on the way toward the clinical translation of antimicrobial coatings have been highlighted.

An aggregation-induced emission immunoassay for broad detection of polychlorinated biphenyls in chicken and crab.

Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) with multiple variants, which may be harmful to human health by absorption and bioaccumulation. To ensure food safety, it is necessary to develop multi-residue immunoassays for broad recognition of PCBs. In this study, by mimicking the generic core structure of PCBs, three haptens have been designed and synthesized for monoclonal antibody (mAb) generation. A carboxylic acid derivative of PCB80 was a hapten that induced a mAb with broad recognition of PCBs. The results of ELISA further identified that the mAb could recognize 11 different kinds of PCBs; half-maximal inhibition concentrations (IC50) ranged from 33.12 to 476.42 ng/mL. Subsequently, using aggregation-induced emission luminogen (AIEgen) nanobeads as the tracer for the output signal, the IC50 value of the various PCBs was improved to 6.38-252.1 ng/mL. The limit of detection (LOD) varied from 0.32 to 42.15 ng/mL. Recoveries of 76.90-95.74% and intra-assay coefficients of variation of 8.5-14.4% were obtained with spiked chicken and crab meat samples. Matrix interference was eliminated by dilution, and no false-positive and false-negative results were observed. The developed assay provides a simple, broad-spectrum, and sensitive tool for detecting PCBs, with high-throughput possibilities for large-scale screening of PCBs in food.

A Polydopamine-Coated Gold Nanoparticles Quenching Quantum Dots-Based Dual-Readout Lateral Flow Immunoassay for Sensitive Detection of Carbendazim in Agriproducts.

In this study, a fluorometric and colorimetric dual-readout lateral flow immunoassay (LFIA) using antibody functionalized polydopamine-coated gold nanoparticles (Au@PDAs) as a probe was developed for the detection of carbendazim (CBD). Colloidal gold nanoparticles (AuNPs) were coated with polydopamines (PDA) by the oxidation of dopamine to synthesize Au@PDA nanoparticles. The Au@PDA nanoparticles mediated ZnCdSe/ZnS quantum dots (QDs) fluorescence quenching and recovery, resulting in a reverse fluorescence enhancement detection format of CBD. The CBD detection was obtained by the competition between the CBD and the immobilized antigen for Au@PDAs labelled antibody binding, resulting in a significant fluorescence increase and colorimetry decrease corresponded to the concentration of CBD. Dual readout modes were incorporated into the LFIA using the colorimetry signal under natural light and the fluorescence signal under UV light. The cut-off value in the mode of the colorimetric signal and fluorometric signal for CBD detection was 0.5 µg/mL and 0.0156 µg/mL, respectively. The sensitivity of LFIA of the fluorescence mode was 32 times higher than that of the colorimetry mode. There was negligible cross reactivity obtained by using LFIA for the determination of thiabendazole, benomyl, thiophanate-methyl, and thiophanate-ethyl. Consistent and satisfactory results have been achieved by comparing the results of Au@PDAs-QDs-LFIA and liquid chromatography-tandem mass spectrometry (LC-MS/MS) testing spiked cucumber and strawberry samples, indicating good reliability of the Au@PDAs-QDs-LFIA.

Dealing with MDR bacteria and biofilm in the post-antibiotic era: Application of antimicrobial peptides-based nano-formulation.

The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.

Bisphenols disrupt thyroid hormone (TH) signaling in the brain and affect TH-dependent brain development in Xenopus laevis.

There is concern about adverse effects of thyroid hormone (TH) disrupting chemicals on TH-dependent brain development. Bisphenol A (BPA) and its analogues, such as bisphenol F (BPF), are known to have the potential to interfere with TH signaling, but whether they affect TH-dependent brain development is not yet well documented. Here, we conducted the T3-induced Xenopus laevis metamorphosis assay, a model for studying TH signaling disruption, to investigate the effects of BPA and BPF (10-1000 nM) on TH signaling in brains and subsequent brain development. While 48-hr treatment with 1 nM T3 dramatically upregulated TH-response gene expression in X. laevis brains at stage 52, 1000 and/or 100 nM BPA also caused significant transcriptional up-regulation of certain TH-response genes, whereas BPF had slighter effects, suggesting limited TH signaling disrupting activity of BPF in brains relative to BPA at the lack of TH. In the presence of 1 nM T3, 1000 and/or 100 nM of BPF as well as BPA antagonized T3-induced TH-response gene expression, whereas lower concentrations agonized T3 actions on certain TH-response genes, displaying an apparently biphasic effect on TH signaling. After 96 h exposure, T3 induced brain morphological remodeling coupled with cell proliferation and neuronal differentiation, whereas both BPA and BPF generally antagonized T3-induced changes in a concentration-dependent manner, with weak or no effects of bisphenol exposure alone. Overall, all results show that BPA and BPF interfered with TH signaling in Xenopus brains, especially in the presence of TH, and subsequently affected TH-dependent brain development. Given the evolutionary conservation of TH-dependent brain development among vertebrates, our findings from X. laevis warrant further studies to reveal potential influences of bisphenols on TH-dependent brain development in higher vertebrates.

Global behavior of a multi-group SEIR epidemic model with age structure and spatial diffusion.

Different epidemic models with one or two characteristics of multi-group, age structure and spatial diffusion have been proposed, but few models take all three into consideration. In this paper, a novel multi-group SEIR epidemic model with both age structure and spatial diffusion is constructed for the first time ever to study the transmission dynamics of infectious diseases. We first analytically study the positivity, boundedness, existence and uniqueness of solution and the existence of compact global attractor of the associated solution semiflow. Based on some assumptions for parameters, we then show that the disease-free steady state is globally asymptotically stable by utilizing appropriate Lyapunov functionals and the LaSalle's invariance principle. By means of Perron-Frobenius theorem and graph-theoretical results, the existence and global stability of endemic steady state are ensured under appropriate conditions. Finally, feasibility of main theoretical results is showed with the aid of numerical examples for model with two groups which is important from the viewpoint of applications.

Fabrication and Adsorption Optimization of Novel Magnetic Core-shell Chitosan/Graphene Oxide/ß-cyclodextrin Composite Materials for Bisphenols in Aqueous Solutions.

A novel magnetic composite material, Fe3O4@SiO2/chitosan/graphene oxide/ß-cyclodextrin (MCGC), was prepared by multi-step methods. Various methods were used to systematically characterize the morphology, composition, structure, and magnetic properties of MCGC. The results obtained show that the composite material has good morphology and crystal structure and can be separated quickly by an external magnetic field. The operation is relatively easy, and the raw materials used to prepare this material are economical, easy to obtain, and environmentally friendly. The performance and adsorption mechanism for using this material as an adsorbent to remove bisphenol A (BPA) and bisphenol F (BPF) from water were studied. The adsorption parameters were optimized. Under optimal conditions, MCGC was found to remove more than 90% of BPA and BPF in a mixed solution (20 mg/L, 50 mL); the adsorption process for BPA and BPF on MCGC was found to follow a Redlich-Peterson isotherm model and Pseudo-second-order kinetic model. The adsorption mechanism for MCGC may involve a combination of various forces. Recycling experiments showed that after five uses, MCGC retained a more than 80% removal effect for BPA and BPF, and through real sample verification, MCGC can be used for wastewater treatment. Therefore, MCGC is economical, environmentally friendly, and easy to separate and collect, and has suitable stability and broad application prospects.

Characterization of Variable Region Genes and Discovery of Key Recognition Sites in the Complementarity Determining Regions of the Anti-Thiacloprid Monoclonal Antibody.

Sequence-defined recombinant antibodies (rAbs) have emerged as alternatives to hybridoma-secreted monoclonal antibodies (mAbs) for performing immunoassays. However, the polyploidy nature of hybridomas often leads to the coexistence of aberrant or non-specific functional variable region (VR) gene transcripts, which complicates the identification of correct VR sequences. Herein, we introduced the use of LC-MS/MS combined with next-generation sequencing to characterize VR sequences in an anti-thiacloprid mAb, which was produced by a hybridoma with genetic antibody diversity. The certainty of VR sequences was verified by the functional analysis based on the recombinant antibody (rAb) expressed by HEK293 mammalian cells. The performance of the rAb was similar to that of the parental mAb, with IC50 values of 0.73 and 0.46 µg/L as measured by ELISAs. Moreover, molecular docking analysis revealed that Ser52 (H-CDR2), Trp98, and Trp93 (L-CDR3) residues in the complementarity determining regions (CDRs) of the identified VR sequences predominantly contributed to thiacloprid-specific recognition through hydrogen bonds and the CH-π interaction. Through single-site-directed alanine mutagenesis, we found that Trp98 and Trp93 (L-CDR3) showed high affinity to thiacloprid, while Ser52 (H-CDR2) had an auxiliary effect on the specific binding. This study presents an efficient and reliable way to determine the key recognition sites of hapten-specific mAbs, facilitating the improvement of antibody properties.