Facile synthesis of boronic acid-functionalized magnetic metal–organic frameworks for selective extraction and quantification of catecholamines in rat plasma

Preparation of branched polyethyleneimine-assisted boronic acid-functionalized magnetic MXene for the enrichment of catecholamines in urine samples

Herein, a magnetic borate-functionalized MXene composite with multiple boronic affinity sites was fabricated by embedding Fe3 O4 nanoparticles with 4-formylphenylboronic acid functionalized Ti3 C2 Tx nanosheets and served as sorbent for the simultaneous extraction of catecholamines (CAs) in urine samples. The morphology and structure of the magnetic materials were investigated using scanning microscopy, vibrating sample magnetometer, X-ray photoelectron spectrometer, and X-ray diffraction. The introduction of polyethyleneimine can amplify the bonded boronic acid groups, thereby effectively improving the adsorption capacities for CAs based on the multiple interactions of boronic affinity, hydrogen bonding, and metal coordination. The adsorption performance was investigated using the kinetics and isotherms models, and the main parameters that influence the extraction efficiency were optimized. Under the most favorable magnetic solid-phase extraction condition, a sensitive method for the analysis of CAs in urine samples was developed by combining magnetic solid-phase extraction conditions with high-performance liquid chromatography detection. The findings illustrated that the proposed approach possessed a wide linearity range of 0.05-250 ng/mL with an acceptable correlation coefficient (R2  ≥ 0.9984) and detection limits of 0.010-0.015 ng/mL for the target CAs. The research not only provides a notable composite with multiple boronic affinity sites but also offers an effective and feasible measure for the detection of CAs in biological samples.

Recent Advances in Catecholamines Analytical Detection Methods and Their Pretreatment Technologies

Catecholamines (CAs), including adrenaline, noradrenaline, and dopamine, are neurotransmitters and hormones that play a critical role in regulating the cardiovascular system, metabolism, and stress response in the human body. As promising methods for real-time monitoring of catecholamine neurotransmitters, LC-MS detectors have gained widespread acceptance and shown significant progress over the past few years. Other detection methods such as fluorescence detection, colorimetric assays, surface-enhanced Raman spectroscopy, and surface plasmon resonance spectroscopy have also been developed to varying degrees. In addition, efficient pretreatment technology for CAs is flourishing due to the increasing development of many highly selective and recoverable materials. There are a few articles that provide an overview of electrochemical detection and efficient enrichment, but a comprehensive summary focusing on analytical detection technology is lacking. Thus, this review provides a comprehensive summary of recent analytical detection technology research on CAs published between 2017 and 2022. The advantages and limitations of relevant methods including efficient pretreatment technologies for biological matrices and analytical methods used in combination with pretreatment technology have been discussed. Overall, this review article provides a better understanding of the importance of accurate CAs measurement and offers perspectives on the development of novel methods for disease diagnosis and research in this field.

[Advances in enrichment and separation of cis-diol-containing compounds by porous organic frameworks]

The design and synthesis of boronate affinity materials that show high efficiency, high selectivity, and high enrichment performance have gained significant attention. The principle of boronate affinity relies on the reversible covalent reactions, including the formation of stable five-membered or six-membered cyclic esters with cis-diol-containing compounds in alkaline aqueous media and dissociation of cyclic esters in an acidic surrounding to release cis-diol-containing compounds. Recently, various boronate affinity materials have been synthesized and utilized for selective enrichment of these compounds. Metal organic frameworks (MOFs) and covalent organic frameworks (COFs) have been widely used in chromatographic separation and sample pretreatment because of their adjustable pore size, high porosity, high specific surface area, tunable skeleton structure, and favorable chemical and thermal stability. To promote the enrichment selectivity of MOFs and COFs for cis-diol-containing compounds, boronic acid-functionalized MOFs and COFs with various structures and categories have been synthesized. This review summarizes more than 80 investigations into the categories, synthetic strategies, and applications of boronic acid-functionalized MOFs and COFs from the Science Citation Index. These synthesis methods include metal ligand-fragment co-assembly, post-synthetic modification, and bottom-up modification of boronic acid-functionalized porous materials. Although two modification strategies (post-synthetic and metal ligand-fragment co-assembly) have been introduced for the preparation of boronic acid-functionalized MOFs, the latter is more commonly adopted as it improves the enrichment selectivity and enrichment efficiency of MOFs. The common limitations of MOFs such as aggregation and aperture issues were also resolved. Boron affinity MOFs possessing favorable properties according to the characteristics of cis-diol-containing compounds, have also been synthesized. Furthermore, to facilitate enrichment and separation, many boronic acid-functionalized magnetic material MOFs have been developed for the enrichment and analysis of cis-diol-containing compounds. Additionally, the luminescent properties of Ln-MOFs have been used in combination with boronic acid affinity for the enrichment, separation, and subsequent detection of cis-diol-containing compounds. Post-synthetic modification and the bottom-up strategy are the primary methods for the preparation of boronic acid-functionalized COFs. Boronic acid-functionalized COFs are less investigated than boronic acid-functionalized MOFs, likely due to the greater complexity of COF synthesis. This work aims to summarize the research advances, synthesis ideas, and synthesis methods related to boric acid-functionalized porous organic frameworks, which will provide theoretical guidance and technical support for its applications while accelerating the commercialization of such organic frameworks.

Magnetite Metal-Organic Frameworks: Applications in Environmental Remediation of Heavy Metals, Organic Contaminants, and Other Pollutants

Due to the increasing environmental pollution caused by human activities, environmental remediation has become an important subject for humans and environmental safety. The quest for beneficial pathways to remove organic and inorganic contaminants has been the theme of considerable investigations in the past decade. The easy and quick separation made magnetic solid-phase extraction (MSPE) a popular method for the removal of different pollutants from the environment. Metal-organic frameworks (MOFs) are a class of porous materials best known for their ultrahigh porosity. Moreover, these materials can be easily modified with useful ligands and form various composites with varying characteristics, thus rendering them an ideal candidate as adsorbing agents for MSPE. Herein, research on MSPE, encompassing MOFs as sorbents and Fe₃O₄ as a magnetic component, is surveyed for environmental applications. Initially, assorted pollutants and their threats to human and environmental safety are introduced with a brief introduction to MOFs and MSPE. Subsequently, the deployment of magnetic MOFs (MMOFs) as sorbents for the removal of various organic and inorganic pollutants from the environment is deliberated, encompassing the outlooks and perspectives of this field.

Advancements on sustainable microbial fuel cells and their future prospects: A review

A microbial fuel cell (MFC) is a sustainable device that produces electricity. The main components of MFC are electrodes (anode & cathode) and separators. The MFC's performance is ascertained by measuring its power density. Its components and other parameters, such as cell design and configuration, operation parameters (pH, salinity, and temperature), substrate characteristics, and microbes present in the substrate, all influence its performance. MFC can be scaled up and commercialized using low-cost materials without affecting its performance. Hence the choice of materials plays a significant role. In the past, precious and non-precious metals were mostly used. These were replaced by a variety of low-cost carbonaceous and non-carbonaceous materials. Nano materials, activated compounds, composite materials, have also found their way as components of MFC materials. This review describes the recently reported modified electrodes (anode and cathode), their improvisation, their merits, pollutant removal efficiency, and associated power density.

Layered Double Hydroxide@Metal-Organic Framework Hybrids for Extraction of Indole-3-Carbinol From Cruciferous Vegetables

Cruciferous vegetables are rich in glucosinolates, which can be metabolized to produce the antitumor compound indole-3-carbinol (I3C). The conventional solvent extraction method for I3C is inefficient. To improve the extraction efficiency of I3C from cruciferous vegetables, we prepared a metal-organic framework (MOF) material (Fe₃O₄@Zn-Al-LDH@B-D-MIL-100). First, Fe₃O₄ nanoparticles were introduced to layered double hydroxides by in situ polymerization. Then, the MOF material was grown on the surface of the layered double hydroxide by co-precipitation and the layer-by-layer self-assembly method. This gave Fe₃O₄@Zn-Al-LDH@B-D-MIL-100, which was characterized using a variety of techniques. The results showed that Fe₃O₄@Zn-Al-LDH@B-D-MIL-100 had a double-layer porous structure, excellent superparamagnetism (11.54955 emu/g), a large specific surface area (174.04 m²/g), and a pore volume (0.26 cm³/g). The extraction conditions for I3C were optimized. Non-linear fitting of the static adsorption model showed that the adsorption was mainly monolayer. Fe₃O₄@Zn-Al-LDH@B-D-MIL-100 had fast adsorption kinetics and could extract 95% of I3C in 45 min. It is superior to the traditional solvent extraction method because of its high enrichment efficiency in a short time and environmental friendliness. The successful preparation of the new nanomaterial will provide a new reference for the enrichment and extraction of the I3C industry.

Current Sample Preparation Methodologies for Determination of Catecholamines and Their Metabolites

Catecholamines (CAs) and their metabolites play significant roles in many physiological processes. Changes in CAs concentration in vivo can serve as potential indicators for the diagnosis of several diseases such as pheochromocytoma and paraganglioma. Thus, the accurate quantification of CAs and their metabolites in biological samples is quite important and has attracted great research interest. However, due to their extremely low concentrations and numerous co-existing biological interferences, direct analysis of these endogenous compounds often suffers from severe difficulties. Employing suitable sample preparation techniques before instrument detection to enrich the target analytes and remove the interferences is a practicable and straightforward approach. To date, many sample preparation techniques such as solid-phase extraction (SPE), and liquid-liquid extraction (LLE) have been utilized to extract CAs and their metabolites from various biological samples. More recently, several modern techniques such as solid-phase microextraction (SPME), liquid-liquid microextraction (LLME), dispersive solid-phase extraction (DSPE), and chemical derivatizations have also been used with certain advanced features of automation and miniaturization. There are no review articles with the emphasis on sample preparations for the determination of catecholamine neurotransmitters in biological samples. Thus, this review aims to summarize recent progress and advances from 2015 to 2021, with emphasis on the sample preparation techniques combined with separation-based detection methods such capillary electrophoresis (CE) or liquid chromatography (LC) with various detectors. The current review manuscript would be helpful for the researchers with their research interests in diagnostic analysis and biological systems to choose suitable sample pretreatment and detection methods.

Flexible organic frameworks sequester neuromuscular blocking agents in vitro and reverse neuromuscular block invivo

Supramolecular sequestration and reversal of neuromuscular block (NMB) have great clinical applications. Water-soluble flexible organic frameworks (FOFs) cross-linked by disulfide bonds are designed and prepared. Different linker lengths are introduced to FOFs to give them varied pore sizes. FOFs are anionic nanoscale polymers and capable of encapsulating cationic neuromuscular blocking agents (NMBAs), including rocuronium (Roc), vecuronium (Vec), pancuronium (Panc) and cisatracurium (Cis). A host–guest study confirms that FOFs bind NMBAs in water. The multivalency interaction between FOFs and NMBAs is able to sequester NMBAs, and prevent them from escaping. These FOFs are non-toxic and biocompatible. Animal studies show that FOFs are effective for the reversal of NMB induced by Roc, Vec and Cis, which shorten the time to a train-of-four ratio of 0.9 by 2.6, 3.8 and 5.7-fold compared to a placebo, respectively.

Water-soluble flexible organic frameworks are prepared and used to sequester neuromuscular blocking agents, and reverse their neuromuscular block in vivo.

A simultaneous extraction/derivatization strategy coupled with liquid chromatography-tandem mass spectrometry for the determination of free catecholamines in biological fluids

The current study presents a convenient, rapid and effective simultaneous extraction/derivatization (SEDP) strategy for effective pretreatment of catecholamines (CAs). Commercial zirconium oxide (ZrO₂) nanoparticles were employed for the selective capturing of cis-diol containing CAs to remove the biological interferences and phenyl isothiocyanate (PITC) was used for derivatization to improve the ionization and to improve the chromatographic separation. The extraction and derivatization procedures were integrated into one step to simplify the sample pretreatment. Excessive derivatization reagents were removed as well, reducing the degree of contaminations in mass spectrometry. The factors affecting the SEDP process were optimized and the results showed that the detection sensitivity and chromatographic separation of CAs greatly improved compared with underivatized CAs, during LC-MS/MS analysis. Combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), quantifying the concentration of norepinephrine (NE), epinephrine (E) and dopamine (DA) in biological fluids was validated in ranges of 1-200.0 ng/mL with a satisfactory correlation coefficient (R² > 0.997). The obtained recoveries were in the range of 91.0-109.5% with RSDs less than 9.4%. Finally, significant changes in CAs levels in urine samples of healthy people and pheochromocytoma patients were detected. The developed method offers comparative advantages in terms of sensitivity, specificity and selectivity.

Tannic acid-directed synthesis of magnetic and boronic acid-functionalized metal-organic frameworks for selective extraction and quantification of catecholamines in human urine

A novel magnetic borate-functionalized metal-organic framework nanocomposite was designed and fabricated for selective enrichment of catecholamines from human urine. Firstly, the polytannic acid (PTA) layer with natural low-cost and ecofriendly polyphenol tannic acid as the organic ligand and Fe³⁺ as the cross-linker was coated onto the surface of Fe₃O₄. Then, the borate-functionalized metal-organic framework (MIL-100(Fe)-B) with 5-boronobenzene-1,3-dicarboxylic acid as a ligand fragment was modified onto the PTA-coated Fe₃O₄ through a metal-ligand-fragment coassembly strategy. The obtained smart porous adsorbent Fe₃O₄@PTA@MIL-100(Fe)-B was confirmed by means of several characterization methods and then applied as an effective magnetic solid phase extraction (MSPE) sorbent for specific extraction of trace catecholamines in human urine. The Plackett-Burman design was used for screening the variables significantly affecting the extraction efficiency. Then, the significant factors were further investigated by the Box-Behnken design to determine the optimal extraction conditions. Under the optimal conditions, a method for selective MSPE combined with high-performance liquid chromatography with a fluorescence detector for the quantitation of catecholamines in human urine was developed and validated. With the proposed method, the linearity range was from 0.500 to 500 ng mL^-1 for norepinephrine and epinephrine and from 1.00 to 500 ng mL^-1 for dopamine. The detection limits were 0.050, 0.11, and 0.20 ng mL^-1 for norepinephrine, epinephrine, and dopamine, respectively. The recoveries from spiking experiments varied from 91.5 to 108% with relative standard deviations (RSDs) of 0.80-4.8%. The established method is rapid, sensitive, accurate, inexpensive, and ecofriendly and was successfully applied to the determination of the target catecholamines in human urine samples.

MG@PD@TiO2 nanocomposite based magnetic solid phase extraction coupled with LC-MS/MS for determination of lysophosphatidylcholines biomarkers of plasma in psoriasis patients

Lysophosphatidylcholine (LPC) was commonly known as a class of significant differential metabolites of high relevance with many diseases including psoriasis, of which the accurate determination is of great importance to diagnosis or prediction to many diseases. However, it is challenging and complicated because of the enormous biological sample complexity and impurities interference. In this study, we synthesized a magnetic nanocomposite MG@PD@TiO₂ and took advantage of the interactions of Lewis acid-base between the phosphate groups in LPCs and Ti ions on MG@PD@TiO₂ nanomaterials for selective separation and enrichment of LPCs from complex biological matrix. The solid-phase extraction sample pretreatment process by means of MG@PD@TiO₂ nanomaterials coupled with LC-MS/MS method was then applied to actual determination of six typical LPCs (LPC 10:0, 14:0, 16:0, 18:0, 18:1, 22:0) in human plasma. The extraction conditions were scientifically optimized by single-factor test (adsorbent amount, adsorption and desorption time, elution solvent type, eluant volume). Under the optimal conditions, the detection limits (LOD, S/N = 3) and quantification limits (LOQ, S/N = 10) were 1 and 5 ng/mL for LPC 10:0 and LPC 14:0, 0.02 and 0.1 ng/mL for LPC 16:0 and LPC 18:1, 0.05 and 0.2 ng/mL LPC 18:0 and LPC 22:0, respectively. The intra- and inter-day precisions were 3.82-12.60 % (n = 6) and 3.29-13.50 % (n = 6) respectively, the recoveries were in the range of 91.92-113.69 % and the stability of the analytes in the matrix performed well with RSDs≤15.51 %. Finally, the developed method was successfully applied to the accurate determination of six LPCs biomarkers of plasma in patients with psoriasis (n = 10) and control groups (n = 10).

Application of magnetic nanomaterials in bioanalysis

The importance of magnetic nanomaterials and magnetic hybrid materials, which are classified as new generation materials, in analytical applications is increasingly understood, and research on the adaptation of these materials to analytical methods has gained momentum. Development of sample preparation techniques and sensor systems using magnetic nanomaterials for the analysis of inorganic, organic and biomolecules in biological samples, which are among the samples that analytical chemists work on most, are among the priority issues. Therefore in this review, we focused on the use of magnetic nanomaterials for the bioanalytical applications including inorganic and organic species and biomolecules in different biological samples such as primarily blood, serum, plasma, tissue extracts, urine and milk. We summarized recent progresses, prevailing techniques, applied formats, and future trends in sample preparation-analysis methods and sensors based on magnetic nanomaterials (Mag-NMs). First, we provided a brief introduction of magnetic nanomaterials, especially their magnetic properties that can be utilized for bioanalytical applications. Second, we discussed the synthesis of these Mag-NMs. Third, we reviewed recent advances in bioanalytical applications of the Mag-NMs in different formats. Finally, recently literature studies on the relevance of Mag-NMs for bioanalysis applications were presented.

Recent development of nanoparticle-assisted metabolites analysis with mass spectrometry

Metabolomics systematically studies the changes of metabolites in biological systems in the temporal or spatial dimensions. It is a challenging task for comprehensive analysis of metabolomics because of diverse physicochemical properties and wide concentration distribution of metabolites. Used as enrichment sorbents, chemoselective probes, chromatographic stationary phases, MS ionization matrix, nanomaterials play excellent roles in improving the selectivity, separation performance, detection sensitivity and identification efficiency of metabolites when mass spectrometry is employed as the detection technique. This review summarized the recent development of nanoparticle-assisted metabolites analysis in terms of assisting the pretreatment of biological samples, improving the separation performance and enhancing the MALDI-MS detection.