Methodology Studies on Detection of Aminoglycoside Residues

Rapid determination of isepamicin by using SERS based on BSA-protected AgNPs modified by α-Fe2O3

A surface-enhanced Raman spectroscopy (SERS) method for the determination of isepamicin (ISE) using silver nanoparticles (AgNPs) protected by bovine serum albumin (BSA) and modified by α-Fe₂O₃ as an efficient substrate was established. The synthesized substrate was characterized and verified by transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-vis), and fourier transform infrared spectroscopy (FT-IR). The conditions affecting the Raman signal of ISE were optimized by single factor and response surface experiments. Under optimized conditions, a standard curve I_SERS = 43.08c + 63598.69 (c: nmol/L) with a linear relationship (r = 0.9976) was established between the SERS intensity and ISE concentration in the range of 20.00 - 2000.00 nmol/L. The limit of detection (LOD) for ISE was 16.58 nmol/L (S/N = 3). The recovery of ISE in the samples was 96.29 % - 104.12 %, with relative standard deviation (RSD) was 1.53 % - 3.43 % (n = 5). The SERS method was reliable and satisfactory for the quantitative analysis of ISE at low concentration.

Rapid Measurement of Residual Kanamycin Using Highly Specific Biomimetic Recognition Paper-Based Chip

The development of highly specific biomimetic recognition material is a challenge for rapid detection of harmful residues in foodstuff. In this study, a paper-based boronate affinity metal-organic framework/molecularly imprinted polymer microfluidic chip (FZS-BA@MIP) was constructed based on the in situ construction strategy, which was also designed as a highly specific biomimetic recognition module. Here, the homogeneous zeolitic imidazole framework-8 (ZIF-8) membrane served as a great scaffold and enrichment layer. Besides, the recognition layer of MIP was prepared based on a highly oriented boronate affinity surface imprinting strategy. With the aid of the liquid flow channel, the highly specific enrichment and visual detection for antibiotic residues like kanamycin in actual products were achieved on the paper chip module of an integrated lateral flow platform. The whole analysis process could be accomplished within 30 min. In brief, this study offered a new integrated biomimetic recognition platform for visually detecting harmful veterinary residues containing cis-diols, which demonstrated promising commercial value in point-of-care testing of foodborne hazardous compounds.

Promoting the Spreading of Droplets on a Superhydrophobic Surface by Supramolecular Amphiphilic Complex-Based Host-Guest Chemistry

The spreading of pesticide droplets on the surface of superhydrophobic plants is an important process, which can prevent the inadequate retention such as bouncing, splashing, and drifting, thereby improving the efficiency of pesticide utilization and reducing soil and groundwater pollution. Herein, we report an approach to fabricate a supramolecular amphiphilic system that significantly contributes to this issue. The hydrophilic amino-pillar[5]arene was synthesized, which could form vesicles with the hydrophobic long-chain guest. This host-guest complex decreased the surface tension, which greatly promotes the spreading of droplets. This study provides a new strategy for prolonging pesticide retention and reducing pesticide loss.

Onsite/on-field analysis of pesticide and veterinary drug residues by a state-of-art technology: A review

Pesticides and veterinary drugs are generally employed to control pests and insects in crop and livestock farming. However, remaining residues are considered potentially hazardous to human health and the environment. Therefore, regular monitoring is required for assessing and legislation of pesticides and veterinary drugs. Various approaches to determining residues in various agricultural and animal food products have been reported. Most analytical methods involve sample extraction, purification (cleanup), and detection. Traditional sample preparation is time-consuming labor-intensive, expensive, and requires a large amount of toxic organic solvent, along with high probability for the decomposition of a compound before the analysis. Thus, modern sample preparation techniques, such as the quick, easy, cheap, effective, rugged, and safe method, have been widely accepted in the scientific community for its versatile application; however, it still requires a laboratory setup for the extraction and purification processes, which also involves the utilization of a toxic solvent. Therefore, it is crucial to elucidate recent technologies that are simple, portable, green, quick, and cost-effective for onsite and infield residue detections. Several technologies, such as surface-enhanced Raman spectroscopy, quantum dots, biosensing, and miniaturized gas chromatography, are now available. Further, several onsite techniques, such as ion mobility-mass spectrometry, are now being upgraded; some of them, although unable to analyze field sample directly, can analyze a large number of compounds within very short time (such as time-of-flight and Orbitrap mass spectrometry). Thus, to stay updated with scientific advances and analyze organic contaminants effectively and safely, it is necessary to study all of the state-of-art technology.

Enrofloxacin/florfenicol loaded cyclodextrin metal-organic-framework for drug delivery and controlled release

We presented an antibiotic-loaded γ-cyclodextrin metal-organic framework that delivered antibiotics suitable for the treatment of bacterial infections. The γ-cyclodextrin metal-organic framework was developed using γ-cyclodextrin and potassium ion via the ultrasonic method. The antibiotic (florfenicol and enrofloxacin) was primarily encapsulated into the pore structures of γ-CD-MOF, which allowed the sustained release of antibiotics over an extended period of time in vitro and in vivo. Notably, antibiotics-loaded γ-CD-MOF showed much superior activity against bacteria than free antibiotics (lower MIC value) and displayed better long-lasting activity (longer antibacterial time). The antibiotics-loaded γ-CD-MOF showed nontoxic and perfect biocompatibility to mammalian cells and tissues both in vitro and in vivo. These materials thus represent a novel drug-delivery device suitable for antibiotic therapy. This research is of great significance for reducing the generation of bacterial resistance and providing new ideas for the application of γ-CD-MOF.

Rapid biosynthesis of fluorescent CdSe QDs in Bacillus licheniformis and correlative bacterial antibiotic change assess during the process

Cadmium selenide (CdSe) quantum dots (QDs) were biosynthesized rapidly in 18 h in Bacillus licheniformis ATCC 11946 (B. licheniformis); this process benefited from the cellular machinery of bacteria metal metabolism, in which inorganic Na₂ SeO₃ and CdCl₂ were chosen as raw materials to produce high quality CdSe QDs by a designed two-step protocol. Research outcomes demonstrated that the purified CdSe QDs possessed maximum fluorescence intensities at weak alkalinity solutions and had good fluorescence stabilities at 4°C as well as at room temperature after standing for 1 week. Glutathione (GSH) concentration and superoxide dismutase (SOD) content, both of which were reported to be greatly related to biosynthetic activities in some bacterial matrices, were monitored during the biosynthetic process in B. licheniformis. Bacterial resistance research further showed that the change in rates in bacterial inhibition zone diameter to seven different antibiotics was less than 9% after B. licheniformis was used to manufacture CdSe QDs, showing a relative lower environmental risk in short-term heavy metal exposure.

Pillar[5]arene Promoted Selective Spreading of Chlormequat Droplets on a Hydrophobic Surface

Promoting the spreading and deposition of agricultural sprays on the crop surface is of great significance for effective utilization of these chemicals. Selective host-guest interaction established between chlormequat and hydroxyl pillar[5]arene was well utilized in the present work for effective spreading of chlormequat droplets over the hydrophobic surface, which was silanized with triethoxy (octyl) silane and then assembled with hydroxybenzene pillar[5]arene molecules. Therefore, this surface was facile for the assembly of chlormequat in droplets and ultimately increased the selective adhesion of chlormequat through host-guest interactions. Moreover, the pillar[5]arene-fabricated surface shows considerable potential applications for rapid detection of chlormequat in environmental monitoring and also provides a novel approach for improving the chlormequat efficiency.

Quantum Dots Applied to Methodology on Detection of Pesticide and Veterinary Drug Residues

The pesticide and veterinary drug residues brought by large-scale agricultural production have become one of the issues in the fields of food safety and environmental ecological security. It is necessary to develop the rapid, sensitive, qualitative and quantitative methodology for the detection of pesticide and veterinary drug residues. As one of the achievements of nanoscience, quantum dots (QDs) have been widely used in the detection of pesticide and veterinary drug residues. In these methodology studies, the used QD-signal styles include fluorescence, chemiluminescence, electrochemical luminescence, photoelectrochemistry, etc. QDs can also be assembled into sensors with different materials, such as QD-enzyme, QD-antibody, QD-aptamer, and QD-molecularly imprinted polymer sensors, etc. Plenty of study achievements in the field of detection of pesticide and veterinary drug residues have been obtained from the different combinations among these signals and sensors. They are summarized in this paper to provide a reference for the QD application in the detection of pesticide and veterinary drug residues.