查找使用阿拉丁产品的科研文献

A highly sensitive electrochemical sensor derived from peptide amphiphilic inspired self-assembled, ordered gold nanoparticles for determination of 22 β-lactams

Yexuan Mao,Yichao Fan,Ran Yang,Youyi Wang,Qingyue Li,Meng Dang,Xianqing Huang,Lianjun Song,Pingan Zhang,Miao Song,Liang Liu,Linli Wang,Shun Yu,Qiuyan Zhao,Xiya Zhang

Achieving ordered arrangement of gold nanoparticles (AuNPs) on an electrode can further improve the signal intensity of an electrochemical immunosensor. This ordered AuNPs self-assembly can be inspired by peptide amphiphile (PA). The rational design of hydrophobic chains in PA is a crucial step when the range of hydrophobic alkane chain from 14 to 18 carbons. As arginine (R) can combine specifically with Au surface plane (111), four PAs, i.e., C 15 H 23 CO-RR (C16R2), C 15 H 23 CO-RRR (C16R3), C 15 H 23 CO-RRRR (C16R4), and C 15 H 23 CO-RRRRR (C16R5), in this work are designed to investigate the extent of ordered AuNPs self-assembly. The results indicate that C16R4 presented a dominant electron donating ability and can inspire the self-assembly of AuNPs to form a mono-dispersed raspberry-like structure (C16R4-AuNPs) to obtain the largest ΔI (15.4 μA). In the detection system, C16R4-AuNPs firstly capture and immobilize anti-β-lactam receptor monoclonal antibodies (mAb) by electrostatic adsorption, and the anti-β-lactam receptor mAb possess antigen-antibody binding sites away from the active site of the receptors. Then, they capture β-lactam receptors through an antigen-antibody reaction to form a ternary complex (C16R4-AuNPs-mAb-β-lactam receptors). Based on this indirect-labeling process, the receptor active sites have been exposed completely, facilitating ligand recognition, which greatly further improves the sensitivity of the present method. Finally, a highly sensitive electrochemical immunosensor based on the ternary complex is developed to achieve the determination of 22 β-lactam antibiotics, which is more sensitive and applicable than other reported electrochemical sensors.

Rapid Determination of Cephalexin in Animal-Derived Food by an Indirect Competitive Enzyme-Linked Immunosorbent Assay

Shuangmin Wu,Wei Shen,Yushuang Chen,Yongli Zhu,Ren Hou,Menghong Dai,Dapeng Peng

Synthesis and Properties of Cefixime Core–Shell Magnetic Nano-Molecularly Imprinted Materials

Li Zhang,Hongbo Mo,Chuan Wang,Xiaofeng Li,Shuai Jiang,Weigang Fan,Yagang Zhang

Novel core–shell magnetic molecularly imprinted polymers (MMIPs) were synthesized using the sol–gel method for the adsorption of cefixime (CFX). Fe3O4@SiO2is the core, and molecularly imprinted polymers (MIPs) are the shell, which can selectively interact with CFX. The preparation conditions, adsorption kinetics, adsorption isotherms, selective adsorption ability, and reutilization performance of the MMIPs were investigated. The adsorption capacity of MMIPs for CFX was 111.38 mg/g, which was about 3.5 times that of MNIPs. The adsorption equilibrium time was 180 min. The dynamic adsorption experiments showed that the adsorption process of MMIPs to CFX conformed to the pseudo-second-order model. Through static adsorption study, the Scatchard analysis showed that MMIPs had two types of binding sites—the high-affinity binding sites and the low-affinity binding sites—while the Langmuir model fit the adsorption isotherms well (R2= 0.9962). Cefepime and ceftiofur were selected as the structural analogs of CFX for selective adsorption studies; the adsorption of CFX by MMIPs was higher than that of other structural analogs; and the imprinting factors of CFX, cefepime, and ceftiofur were 3.5, 1.7, and 1.4, respectively. Furthermore, the MMIPs also showed excellent reusable performance.

β-Cyclodextrin functionalized N,Zn codoped carbon dots for specific fluorescence detection of fluoroquinolones in milk samples

Yueran Zhu,Yunguang Lu,Longyan Shi,Yaling Yang

A green, reliable and simple assay for Fluoroquinolone derivatives (FQs) is developed based on Mono-(6-Amino-6-Deoxy)-β-Cyclodextrin (β-CD) were modified on the surface of N,Zn co-doped carbon dots (N,Zn-CDs). FQs not only enhance β-CD-N,Zn-CDs fluorescence intensity, but also red-shift. Since FQs has the same effect on the fluorescence of β-CD-N,Zn-CDs, so ofloxacin (OFL) as a representative for analysis. Under optimized detection conditions, the linear range is 0.075–3.75 μM and the LOD is 0.05 μM (S/N = =3). Finally, the proposed method was successfully applied in the determination of OFL in milk and domestic water with satisfactory recoveries.

Degradation of β-lactam antibiotics by Fe(III)/HSO3− system and their quantitative structure-activity relationship

Zhenbin Chen,Haohan Cai,Feng Huang,Zongping Wang,Yiqun Chen,Zizheng Liu,Pengchao Xie

β-lactam antibiotics, extensively used worldwide, pose significant risks to human health and ecological safety due to their accumulation in the environment. Recent studies have demonstrated the efficacy of transition metal-activated sulfite systems, like Fe(Ⅲ)/HSO 3 − , in removing PPCPs from water. However, research on their capability to degrade β-lactam antibiotics remains sparse. This paper evaluates the degradation of 14 types of β-lactam antibiotics in Fe(Ⅲ)/HSO 3 − system and establishes a QSAR model correlating molecular descriptors with degradation rates using the MLR method. Using cefazolin as a case study , this research predicts degradation pathways through NPA charge and Fukui function analysis, corroborated by UPLC-MS product analysis. The investigation further explores the influence of variables such as HSO 3 − dosage, substrate concentration , Fe(Ⅲ) dosage, initial pH and the presence of common seen water matrices including humic acid and bicarbonate on the degradation efficiency. Optimal conditions for cefazolin degradation in Fe(Ⅲ)/HSO 3 − system were determined to be 93.3 μM HSO 3 − , 8.12 μM Fe(Ⅲ) and an initial pH of 3.61, under which the interaction of Fe(Ⅲ) dosage with initial pH was found to significantly affect the degradation efficiency. This study not only provides a novel degradation approach for β-lactam antibiotics but also expands the theoretical application horizon of the Fe(Ⅲ)/HSO 3 − system.

Bacteria-Responsive Drug Delivery System Utilizing Carboxymethyl Cellulose-Functionalized Metal–Organic Framework for Enhanced Antibacterial Efficacy

Pingping Yuan,Mengying Zhang,Sheng Wang,Lin Li,Runan Zuo,Shaoqi Qu

Bacterial infections pose a significant threat to human health and economic stability. The overuse of antibiotics has exacerbated bacterial resistance, highlighting the urgent need for innovative strategies to combat this issue. Bacteria-responsive drug delivery systems present a promising solution to overcoming bacterial resistance. Metal–organic frameworks (MOFs), versatile porous materials created by linking metal clusters with organic ligands, are ideal candidates for such applications. Here, we employed the zeolite imidazole framework 8 (ZIF-8) as a carrier for ceftiofur (EFT), enhanced with carboxymethyl cellulose to develop a smart drug delivery system (CMC-EFT@ZIF-8) responsive to pH and cellulase. In vitro tests demonstrated that this system released a higher quantity of EFT under acidic conditions and in the presence of cellulase, leading to more effective disruption of bacterial membranes and subsequent bacterial death. The CMC-EFT@ZIF-8 system achieved a 99% clearance of Pseudomonas aeruginosa within 6 h and showed superior efficacy in a mouse skin wound model. These findings underscore the potential of our smart drug delivery system to significantly improve treatment outcomes for bacterial infections, representing a significant advancement in the fight against antibiotic resistance.

A group-targeting biosensor for sensitive and rapid detection of quinolones in water samples

Bohan Wang,Lanhua Liu,Haopeng Zhang,Zhiqiang Wang,Kang Chen,Bo Wu,Limin Hu,Xiaohong Zhou,Lanlan Liu

Background Quinolones (QNs) widely exist in the environment due to their wide range of applications and poor metabolic properties, resulting in the generation and spread of resistance genes, posing a potential threat to human health. Traditional analytical methods cannot detect all broad ranges of QNs simultaneously. The development of facile, efficient and reliable method for quantification and assessment of the total QNs is a long-lasting challenge. Results We hereby provide a simple, sensitive and instantaneous group-targeting biosensor for the detection of total QNs in environmental water samples. The biosensor is based on a group-specific antibodies with high affinity against QNs. Fluorescent labeled antibodies bound to the coated antigen modified on the surface of the transducer, and excited by the evanescent waves. The detected fluorescent signal is inversely proportional to the QNs concentration. This biosensor exhibited excellent performance with detection limits lower than 0.15 μg L −1 for all five QNs variants, and even lower than 0.075 μg L −1 for ciprofloxacin (CIP) and ofloxacin (OFL). Environmental water samples can be detected after simple pretreatment, and all detection steps can be completed in 10 min. The transducer has a high regenerative capacity and shows no significant signal degradation after two hundred detection cycles. The recoveries of QNs in a variety of wastewater range from 105 to 119%, confirming its application potential in the measurement of total QNs in reality. Significance The biosensor can realize rapid and sensitive detection of total QNs in water samples by simple pretreatment, which overcomes the disadvantage of the traditional methods that require complex pretreatment and time-consuming, and pave the groundwork for expansive development centered around this technology.

Penicillin-Binding Proteins and Graphene/Chitosan Nanocomposite-Based Electrochemical Assay for Multiple Beta-Lactam Antibiotics Detection in Milk

Senwei Jiang,Hangzhen Lan,Daodong Pan,Lu Huang,Yichun Wu

Beta-lactam antibiotics (BLAs) are not only important in animal husbandry but are also unavoidable contaminants in milk. The gradual accumulation of BLAs in the human body due to increased milk intake can cause direct harm to human health. Therefore, developing selective and sensitive methods for rapid BLA detection is essential. In this study, a specific electrochemical receptor sensor based on penicillin-binding proteins (PBPs) was established. PBP1a and PBP2x, which have high affinity and specificity for the six BLAs, were used as the receptors and their performance was compared. The sensor was fabricated by sequentially immobilizing a graphene/chitosan nanocomposite, penicillin G (PENG), and Nafion on the surface of a glassy carbon electrode using a convenient casting approach. The mechanism of the electrochemical receptor sensor involved direct competitive inhibition of the binding of the graphene/chitosan/PENG composite to the PBPs by the free BLAs in the solution. The PENG-PBPs complex resisted the interaction between [Fe(CN) 6 ] 3−/4− ions and the glassy carbon electrode, thereby decreasing the current signal of the BLAs. The BLA concentration was quantified using differential pulse voltammetry mode. The graphene/PENG/chitosan/Nafion-based electrochemical assay demonstrated good selectivity against other antibiotic residues frequently detected in milk. Under optimized conditions, the detection limits of this method ranged from 0.24 to 1.39 ng·mL −1 , which are much lower than the maximum residue limits set by China and the EU. Moreover, the sensor showed a satisfactory recovery rate of 98.8 ± 5.8%–103.2 ± 7.1%. The total analysis time involved only one incubation step, and the entire analysis could be completed within 35 min.

Penicillin binding proteins-based immunoassay for the selective and quantitative determination of beta-lactam antibiotics

Rilong Liu,Hangzhen Lan,Song Yan,Lu Huang,Daodong Pan,Yichun Wu

An immunoassay method based on penicillin-binding protein (PBP) was developed for the quantitative determination of 10 kinds of beta-lactam antibiotics (BLAs). First, two kinds of PBPs, which are named PBP1a and PBP2x, were expressed and purified, and they were characterized by SDS-PAGE and western blotting analysis. Then, the binding activity of PBP1a and PBP2x to template BLAs, cefquinome (CEFQ) and ampicillin (AMP), was determined. The effect of the buffer solution system, e.g., pH, ion concentration, and organic solvent, on the immune interaction efficiency between PBPs and BLAs was also evaluated. In the end, the PBP-based immunoassay method was developed and validated for the detection of 10 kinds of BLAs. Under optimal conditions, PBPs exhibited high binding affinity to BLAs. In addition, this method showed a high sensitivity for the detection of 10 kinds of BLAs with the limits of detection from 0.21 to 9.12 ng/mL, which are much lower than their corresponding maximum residual limit of European Union (4–100 ng/mL). Moreover, the developed PBP-immunoassay was employed for BLA detection from milk samples, and satisfactory recoveries (68.9–101.3 %) were obtained.

Lon dysfunction-mediated collateral sensitivity drives effective antibiotic combination therapies against tigecycline-resistant pathogens

Feiyu Yu,Shuyao Zhu,Qingyang Lv,Dan Fang,Haijie Zhang,Zhiqiang Wang,Yuan Liu

Tigecycline is a last-resort antibiotic primarily used to treat severe infections caused by multidrug-resistant (MDR) bacteria. However, the emergence of constantly appearing resistance determinants has drastically compromised its clinical effectiveness. Rational antibiotic combination provides a productive approach to tackle MDR pathogens. Herein, we show that evolved tigecycline-resistant Escherichia coli and Salmonella Enteritidis exhibit collateral sensitivity to aminoglycosides and nitrofurantoin. Proton motive force alterations mediate tigecycline resistance, simultaneously enhancing bacterial susceptibility to aminoglycosides. Notably, Lon dysfunction in tigecycline-resistant strains causes overexpression of sulA , increased lipopolysaccharide biosynthesis, and disrupted membrane homeostasis, leading to bacterial death upon nitrofurantoin exposure. The combination of tigecycline and nitrofurantoin effectively eradicates both evolved tigecycline-resistant bacteria and those carrying the tet (X4) gene while also hindering the development of tigecycline resistance. Together, our study suggests that combining tigecycline with existing antibiotics, rationally designed by harnessing collateral sensitivity, represents a promising therapeutic paradigm to combat tigecycline-resistant pathogens.