Preparation of molecularly imprinted polymers and application in a biomimetic biotin-avidin-ELISA for the detection of bovine serum albumin

Pharmaceutical Applications of Biomass Polymers: Review of Current Research and Perspectives

Polymers derived from natural biomass have emerged as a valuable resource in the field of biomedicine due to their versatility. Polysaccharides, peptides, proteins, and lignin have demonstrated promising results in various applications, including drug delivery design. However, several challenges need to be addressed to realize the full potential of these polymers. The current paper provides a comprehensive overview of the latest research and perspectives in this area, with a particular focus on developing effective methods and efficient drug delivery systems. This review aims to offer insights into the opportunities and challenges associated with the use of natural polymers in biomedicine and to provide a roadmap for future research in this field.

Precise detection of trace level protein using MIP-MoS2 nanocomposite functionalized PCF based interferometer

Fiber optic interferometry combined with recognizing elements has attracted intensive attention for the development of different biosensors due to its superior characteristic features. However, the immobilization of sensing elements alone is not capable of low-concentration detection due to weak interaction with the evanescent field of the sensing transducer. The utilization of different 2D materials with high absorption potential and specific surface area can enhance the intensity of the evanescent field and hence the sensitivity of the sensor. Here, a biosensor has been fabricated using an inline hetero fiber structure of photonic crystal fiber (PCF) and single-mode fiber (SMF) functionalized with a nanocomposite of molybodenum di-sulfide (MoS2) and molecular imprinting polymer (MIP) to detect trace levels of bovine serum albumin (BSA). The sensor showed a wide dynamic detection range with a high sensitivity of 2.34 × 107 pm/µg L-1. It shows working potential over a wide pH range with a subfemtomolar detection limit. The compact size, easy fabrication, stable structure, long detection range, and high sensitivity of this sensor would open a new path for the development of different biosensors for online and remote sensing applications.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.

Molecularly imprinted polymers as effective capturing receptors in a pseudo-ELISA immunoassay for procalcitonin detection in veterinary species

In this study, a new sandwich-type immunoenzymatic assay, based on a molecularly imprinted polymer (MIP) as an artificial antibody (pseudo-ELISA), was developed for the determination of procalcitonin (PCT) in veterinary species. The quantification of PCT in human medicine represents the state of the art for the diagnosis of sepsis; instead the clinical studies on the relevance of PCT as a sepsis predictor in veterinary patients are few, likely due to the total absence of validated assays. MIPs have been widely used as antibody mimics for important applications, and MIP-based sandwich assays have emerged as promising analytical tools for the detection of disease biomarkers. Herein, a polynorepinephrine (PNE)-based imprinted film was directly synthesized on the well surface of a 96-well plate. Subsequently, based on a commercial ELISA kit, the PCT quantification was accomplished via a colorimetric sandwich assay by replacing the capture antibody of the kit with the PNE-based MIP. This method was performed to detect canine and equine PCT in buffer and in plasma samples. Under optimal conditions, the results obtained in plasma samples showed a limit of detection (LOD) of 5.87 ng mL^-1 and a reproducibility (CV_av%) of 10.0% for canine samples, while a LOD = 4.46 ng mL^-1 and CV_av% = 7.61% were obtained for equine samples.

Functional Properties and Extraction Techniques of Chicken Egg White Proteins

Chicken egg whites contain hundreds of proteins, and are widely used in the food, biological and pharmaceutical industries. It is highly significant to study the separation and purification of egg white proteins. This review first describes the structures and functional properties of several major active proteins in egg whites, including ovalbumin, ovotransferrin, ovomucoid, lysozyme, ovomucin, ovomacroglobulin and avidin. Then, the common techniques (including precipitation, chromatography and membrane separation) and some novel approaches (including electrophoresis, membrane chromatography, aqueous two-phase system and molecular imprinting technology) for the separation and purification of egg white proteins broadly reported in the current research are introduced. In addition, several co-purification methods for simultaneous separation of multiple proteins from egg whites have been developed to improve raw material utilization and reduce costs. In this paper, the reported techniques in the last decade for the separation and purification of chicken egg white proteins are reviewed, discussed and prospected, aiming to provide a reference for further research on egg proteins in the future.

Enzyme Encapsulation by Facile Self-Assembly Silica-Modified Magnetic Nanoparticles for Glucose Monitoring in Urine

Silica nanoparticles hold tremendous potential for the encapsulation of enzymes. However, aqueous alcohol solutions and catalysts are prerequisites for the production of silica nanoparticles, which are too harsh for maintaining the enzyme activity. Herein, a procedure without any organic solvents and catalysts (acidic or alkaline) is developed for the synthesis of silica-encapsulated glucose-oxidase-coated magnetic nanoparticles by a facile self-assembly route, avoiding damage of the enzyme structure in the reaction system. The encapsulated enzyme was characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, and a vibrating sample magnetometer. Finally, a colorimetric sensing method was developed for the detection of glucose in urine samples based on the encapsulated glucose oxidase and a hydrogen peroxide test strip. The method exhibited a good linear performance in the concentration range of 20~160 μg mL⁻¹ and good recoveries ranging from 94.3 to 118.0%. This work proves that the self-assembly method could be employed to encapsulate glucose oxidase into silica-coated magnetic particles. The developed colorimetric sensing method shows high sensitivity, which will provide a promising tool for the detection of glucose and the monitoring of diabetes.

A biomimetic enzyme-linked immunosorbent assay (BELISA) for the analysis of gonadorelin by using molecularly imprinted polymer-coated microplates

An original biomimetic enzyme-linked immunoassay (BELISA) to target the small peptide hormone gonadorelin is presented. This peptide has been recently listed among the substances banned in sports by the World Antidoping Agency (WADA) since its misuse by male athletes triggers testosterone increase. Hence, in response to this emerging issue in anti-doping controls, we proposed BELISA which involves the growth of a polynorepinephrine (PNE)–based molecularly imprinted polymer (MIP) directly on microwells. PNE, a polydopamine (PDA) analog, has recently displayed impressive performances when it was exploited for MIP preparation, giving even better results than PDA. Gonadorelin quantification was accomplished via a colorimetric indirect competitive bioassay involving the competition between biotinylated gonadorelin linked to the signal reporter and the unlabeled analyte. These compete for the same MIP binding sites resulting in an inverse correlation between gonadorelin concentration and the output color signal (λ = 450 nm). A detection limit of 277 pmol L⁻¹ was achieved with very good reproducibility in standard solutions (_avCV% = 4.07%) and in urine samples (_avCV% = 5.24%). The selectivity of the assay resulted adequate for biological specimens and non-specific control peptides. In addition, the analytical figures of merit were successfully validated by mass spectrometry, the reference anti-doping benchtop platform for the analyte. BELISA was aimed to open real perspectives for PNE-based MIPs as alternatives to antibodies, especially when the target analyte is a poorly or non-immunogenic small molecule, such as gonadorelin.

Fabrication of human serum albumin–imprinted photothermal nanoparticle for enhanced immunotherapy

Photothermal nanoparticles have been confirmed to induce antitumor immune response and turn “cold tumor” into “hot tumor”. However, their delivery efficacy to tumors is limited by the elimination from the...

Bovine Serum Albumin Conjugation in Superparamagnetic/Poly(methyl methacrylate) Nanoparticles as an Alternative for Magnetic Enzyme-Linked Immunosorbent Assays

Nanomaterials, such as magnetic nanoparticles have attracted significant attention of medical area due to their capacity to improve the performance of immunoassays. Therefore the aim of this work was to study the bovine serum albumin (BSA) conjugation in superparamagnetic (MNPs)/poly(methyl methacrylate) (PMMA) nanoparticles with further characterization and application in enzyme-linked immunosorbent (ELISA) assay. The successful conjugation of BSA in MNPs- PMMA nanoparticles was confirmed by several techniques, including light scattering, zeta potential, transmission electron microscopy (TEM) and Lowry protein quantification assay. The superparamagnetic properties were confirmed by vibrating sample magnetometer. BSA conjugated MNPs-PMMA nanoparticles presented higher interactions with antibody than free BSA. The BSA + MNPs-PMMA nanoparticles (magnetic ELISA assay) reduced the time and increased the sensibility of traditional ELISA assay, reinforcing the idea that the use these nanomaterials are an excellent alternative for the immunoassays field.

Recent advances in developing optical and electrochemical sensors for analysis of methamphetamine: A review

Recognition of misused stimulant drugs has always been a hot topic from a medical and judicial perspective. Methamphetamine (MAMP) is an addictive and illegal drug that profoundly affects the central nervous system. Like other illicit drugs, the detection of MAMP in biological and street samples is vital for several organizations such as forensic medicine, anti-drug headquarters and diagnostic clinics. By emerging nanotechnology and exploiting nanomaterials in sensing applications, a great deal of attention has been given to the design of analytical sensors in MAMP tracing. For the first time, this study has briefly reviewed all the optical and electrochemical sensors in MAMP detection from earlier so far. How various receptors with engineering nanomaterials allow developing novel approaches to measure MAMP have been studied. Fundamental concepts related to optical and electrochemical recognition assays in which nanomaterials have been used and relevant MAMP sensing applications have been comprehensively covered. Challenges, opportunities and future outlooks of this field have also been discussed at the end.

Environmental impact of molecularly imprinted polymers used as analyte sorbents in mass spectrometry

The molecularly imprinted polymers (MIPs) with the following herbicides used as templates 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-chloro-2-methylphenoxy- acetic acid (MCPA) were synthesized by precipitation polymerization technique using 4-vinylpyridine (4-VP) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator in methanol solvent. For the flavonoid MIPs, rutin (Ru) and quercetin (Q) were used as templates and synthesized via a similar technique, utilizing acrylamide (AA) as a functional monomer. Analysis of binding in the molecularly imprinted and non-imprinted polymer (NIP) has proved that MIP shows a higher affinity towards the analytes, compared to NIP. MIP was used to determine analytes in water using the Flowing Atmospheric-Pressure Afterglow Mass Spectrometry (FAPA-MS) technique. In this approach, the method limit of detection (MLOD) of 2,4-D, MCPA, Ru, and Q in MIP was 4, 3, 10, and 5 μg in 1 g MIP, respectively. The release kinetics of the analytes from MIP and their stability in water was studied. The cultures of Tetradesmus obliquus (Turpin) M.J. Wynne and Daphnia magna Straus were used for in vivo toxicity studies revealing that only Ru-MIP and Q-MIP had negative effect on the living organisms used in the bioassays.

Magnetic molecularly imprinted polymer nanoparticles for the extraction and clean-up of thiamethoxam and thiacloprid in light and dark honey

In this work, new selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) were synthesized and characterized. Sorbent MIPs were investigated for simultaneous extraction and clean-up of thiamethoxam and thiacloprid from light and dark honey samples. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry triple-quadrupole (UHPLC-MS/MS) (QQQ) was used to detect and quantify the pesticides. The kinetic model with adsorption kinetics of sorbent was investigated. The optimal adsorption conditions were 80 mg of polymer MIPs, a 30-min extraction time, and a pH of 7. The detection limit (LOD) and the quantification limit (LOQ) varied from 0.045 to 0.070 µg kg^-1 and from 0.07 to 0.10 µg kg^-1, respectively. The intra-day and inter-day precision (RSD, %) ranged from 1.3 to 2.0% and from 8.2 to 12.0%, respectively. The recovery of thiamethoxam and thiacloprid ranged from 96.8 to 106.5% and 95.3 to 104.4%, respectively, in light and dark honey samples.

A surfactant-mediated sol-gel method for the preparation of molecularly imprinted polymers and its application in a biomimetic immunoassay for the detection of protein

Molecularly imprinted polymers have demonstrated tremendous potential in the immunoassay as alternatives to biological antibodies. However, the production of molecularly imprinted polymers for protein remains great challenges because of structural complexity and organic solvent instability. In addition, non-specific binding sites in the molecularly imprinted polymers debase the feasibility of it as alternative to antibodies for immunoassay. Here, a surfactant-mediated sol-gel system in an aqueous environment was designed to produce the molecularly imprinted polymers for protein. A blocked strategy was introduced to decrease non-specific cross-reactivity and to improve the selectivity. The developed products were characterized by infrared spectroscopy, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, and vibrating sample magnetometer, respectively. The obtained molecularly imprinted polymers exhibited desirable specific recognition towards the target and a biomimetic immunoassay method was developed. The method exhibited a good linear response to human serum albumin in a concentration range of 1-100 μg mL^-1. The limit of detection of this method was 0.3 μg mL^-1 (3s/K), and good recoveries ranging from 85.4-104.5% were achieved. This study demonstrated that the molecularly imprinted polymers prepared by the surfactant-mediated sol-gel method can produce high selectivity materials, which had great potential to replace antibodies in a biomimetic immunoassay.

Facile one-step targeted immobilization of an enzyme based on silane emulsion self-assembled molecularly imprinted polymers for visual sensors

Immobilized enzymes play significant roles in many practical applications. However, the enzymes need to be purified before immobilization by conventional immobilizing methods, and the purification process is expensive, laborious, complicated and results in a decrease of the enzymatic activity. So, we present a novel method by a facile one-step targeted immobilization of an enzyme without a purification process from complex samples. For this purpose, a novel molecularly imprinted polymer was prepared via a silane emulsion self-assembly method using boric acid-modified Fe3O4 nanoparticles as magnetic nuclei, horseradish peroxidase as a template, 3-aminopropyltriethoxysilane as a functional monomer and tetraethyl orthosilicate as a crosslinking agent. The molecularly imprinted polymers were characterized using a scanning electron microscope, X-ray photoelectron spectroscope, vibrating sample magnetometer and X-ray diffractometer. The as-prepared and characterized materials were employed to immobilize horseradish peroxidase from a crude extract of horseradish. Moreover, the immobilized horseradish peroxidase was employed to develop visual sensors for the detection of glucose and sarcosine. This study demonstrated that the molecularly imprinted polymers prepared via the silane emulsion self-assembly method can facilely immobilize horseradish peroxidase from a crude extract of horseradish without any purification process. The developed visual method based on the immobilized horseradish peroxidase shows great potential applications for the visual detection of glucose and sarcosine.

Fluorescent biosensor based on magnetic cross-linking enzyme aggregates/CdTe quantum dots for the detection of H2O2-bioprecursors

A fluorescent sensing system for H₂O₂-bioprecursors based on CdTe quantum dots and magnetic cross-linking enzyme aggregates was designed.

CdS quantum dots-based immunoassay combined with particle imprinted polymer technology and laser ablation ICP-MS as a versatile tool for protein detection

For the first time, the combination of molecularly imprinted polymer (MIP) technology with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is presented with focus on an optimization of the LA-ICP-MS parameters such as laser beam diameter, laser beam fluence, and scan speed using CdS quantum dots (QDs) as a template and dopamine as a functional monomer. A non-covalent imprinting approach was employed in this study due to the simplicity of preparation. Simple oxidative polymerization of the dopamine that creates the self-assembly monolayer seems to be an ideal choice. The QDs prepared by UV light irradiation synthesis were stabilized by using mercaptosuccinic acid. Formation of a complex of QD-antibody and QD-antibody-antigen was verified by using capillary electrophoresis with laser-induced fluorescence detection. QDs and antibody were connected together via an affinity peptide linker. LA-ICP-MS was employed as a proof-of-concept for detection method of two types of immunoassay: 1) antigen extracted from the sample by MIP and subsequently overlaid/immunoreacted by QD-labelled antibodies, 2) complex of antigen, antibody, and QD formed in the sample and subsequently extracted by MIP. The first approach provided higher sensitivity (MIP/NIP), however, the second demonstrated higher selectivity. A mixture of proteins with size in range 10–250 kDa was used as a model sample to demonstrate the capability of both approaches for detection of IgG in a complex sample.

Magnetic carbon nanotube modified with polymeric deep eutectic solvent for the solid phase extraction of bovine serum albumin

This article described the fabrication of novel magnetic carbon nanotube modified with polymeric deep eutectic solvent (M-CNT@PDES) and its application as extractant for the magnetic solid phase extraction (MSPE) of bovine serum albumin (BSA). The physicochemical properties and morphology of M-CNT@PDES were characterized by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermo-gravimetric analysis (TGA), zeta potentials, fourier transform infrared spectrometry (FT-IR) and transmission electron microscope (TEM). Afterwards, several parameters such as pH value, initial concentration of BSA, extraction time, ionic strength and extraction temperature were optimized. The results indicated that the modification of PDES significantly improved the extraction performance for BSA, and the maximum extraction capacity was 225.15 mg/g under the optimized conditions. In addition, 0.20 mol/L NaCl-PBS solution was chosen as the appropriate eluent, and favourable elution rate (81.22%) was obtained. Circular dichroism spectroscopy (CD) indicated that the secondary structure of BSA has not changed during extraction and elution. The regenerative experiment and application in real calf serum confirmed the outstanding durability and practical application ability of M-CNT@PDES. All of above verified that the proposed M-CNT@PDES coupled with MSPE method has great application potential for the pre-concentration of biomolecules.

A Simple and Efficient Molecularly Imprinted Electrochemical Sensor for the Selective Determination of Tryptophan

In this paper, a tryptophan (Trp) molecularly imprinted chitosan film was prepared on the surface of an acetylene black paste electrode using chitosan as the functional polymer, Trp as the template molecule and sulfuric acid as the crosslinking agent. The surface morphologies of non-imprinted and imprinted electrodes were characterized by scanning electron microscopy (SEM). The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. Some factors affecting the performance of the imprinted electrode such as the concentration of chitosan, the mass ratio of chitosan to Trp, the dropping amount of the chitosan-Trp mixture, the solution pH, and the accumulation potential and time were discussed. The experimental results show that the imprinted electrode exhibit good affinity and selectivity for Trp. The dynamic linear ranges of 0.01–4 μM, 4–20 μM and 20–100 μM were obtained by second derivative linear sweep voltammetry, and the detection limit was calculated to be 8.0 nM. The use of the imprinted electrode provides an effective method for eliminating the interference of potentially interfering substances. In addition, the sensor has high sensitivity, reproducibility and stability, and can be used for the determination of Trp in pharmaceutical preparations and human serum samples.