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1.
Int J Mol Sci ; 25(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731823

RESUMO

This study presents the initial attempt at introducing a magnetic molecularly imprinted polymer (MIP) designed specifically for lamotrigine with the purpose of functioning as a drug carrier. First, the composition of the magnetic polymer underwent optimization based on bulk polymer adsorption studies and theoretical analyses. The magnetic MIP was synthesized from itaconic acid and ethylene glycol dimethacrylate exhibiting a drug loading capacity of 3.4 ± 0.9 µg g-1. Structural characterization was performed using powder X-ray diffraction analysis, vibrating sample magnetometry, and Fourier transform infrared spectroscopy. The resulting MIP demonstrated controlled drug released characteristics without a burst effect in the phospahe buffer saline at pH 5 and 8. These findings hold promise for the potential nasal administration of lamotrigine in future applications.


Assuntos
Portadores de Fármacos , Lamotrigina , Polímeros Molecularmente Impressos , Lamotrigina/química , Portadores de Fármacos/química , Polímeros Molecularmente Impressos/química , Polímeros Molecularmente Impressos/síntese química , Impressão Molecular/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Liberação Controlada de Fármacos , Difração de Raios X , Adsorção , Concentração de Íons de Hidrogênio
2.
Mikrochim Acta ; 191(6): 332, 2024 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748375

RESUMO

Nifedipine (NIF), as one of the dihydropyridine calcium channel blockers, is widely used in the treatment of hypertension. However, misuse or ingestion of NIF can result in serious health issues such as myocardial infarction, arrhythmia, stroke, and even death. It is essential to design a reliable and sensitive detection method to monitor NIF. In this work, an innovative molecularly imprinted polymer dual-emission fluorescent sensor (CDs@PDA-MIPs) strategy was successfully designed for sensitive detection of NIF. The fluorescent intensity of the probe decreased with increasing NIF concentration, showing a satisfactory linear relationship within the range 1.0 × 10-6 M ~ 5.0 × 10-3 M. The LOD of NIF was 9.38 × 10-7 M (S/N = 3) in fluorescence detection. The application of the CDs@PDA-MIPs in actual samples such as urine and Qiangli Dingxuan tablets has been verified, with recovery ranging from 97.8 to 102.8% for NIF. Therefore, the fluorescent probe demonstrates great potential as a sensing system for detecting NIF.


Assuntos
Carbono , Dopamina , Corantes Fluorescentes , Limite de Detecção , Polímeros Molecularmente Impressos , Nifedipino , Pontos Quânticos , Espectrometria de Fluorescência , Pontos Quânticos/química , Nifedipino/química , Nifedipino/análise , Corantes Fluorescentes/química , Polímeros Molecularmente Impressos/química , Dopamina/urina , Dopamina/análise , Carbono/química , Espectrometria de Fluorescência/métodos , Humanos , Polimerização , Impressão Molecular , Comprimidos/análise
3.
Sci Rep ; 14(1): 10293, 2024 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704412

RESUMO

In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting approach. The magnetic molecularly imprinted polymer (MIP) nanocomposite was prepared using pirimicarb as the template molecule, CuFe2O4 nanoparticles, and graphene quantum dots as a fluorophore (MIP-CuFe2O4/GQDs). It was then characterized using X-ray diffraction (XRD) technique, Fourier transforms infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The response surface methodology (RSM) was also employed to optimize and estimate the effective parameters of pirimicarb adsorption by this polymer. According to the experimental results, the average particle size and imprinting factor (IF) of this polymer are 53.61 nm and 2.48, respectively. Moreover, this polymer has an excellent ability to adsorb pirimicarb with a removal percentage of 99.92 at pH = 7.54, initial pirimicarb concentration = 10.17 mg/L, polymer dosage = 840 mg/L, and contact time = 6.15 min. The detection of pirimicarb was performed by fluorescence spectroscopy at a concentration range of 0-50 mg/L, and a sensitivity of 15.808 a.u/mg and a limit of detection of 1.79 mg/L were obtained. Real samples with RSD less than 2 were measured using this chemosensor. Besides, the proposed chemosensor demonstrated remarkable selectivity by checking some other insecticides with similar and different molecular structures to pirimicarb, such as diazinon, deltamethrin, and chlorpyrifos.


Assuntos
Praguicidas , Pirimidinas , Praguicidas/análise , Carbamatos/análise , Carbamatos/química , Pontos Quânticos/química , Polímeros Molecularmente Impressos/química , Polímeros/química , Espectrometria de Fluorescência/métodos , Grafite/química , Impressão Molecular/métodos , Adsorção , Limite de Detecção , Espectroscopia de Infravermelho com Transformada de Fourier , Nanocompostos/química , Nanocompostos/ultraestrutura
4.
Nat Commun ; 15(1): 3731, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702306

RESUMO

Molecular recognition of proteins is key to their biological functions and processes such as protein-protein interactions (PPIs). The large binding interface involved and an often relatively flat binding surface make the development of selective protein-binding materials extremely challenging. A general method is reported in this work to construct protein-binding polymeric nanoparticles from cross-linked surfactant micelles. Preparation involves first dynamic covalent chemistry that encodes signature surface lysines on a protein template. A double molecular imprinting procedure fixes the binding groups on the nanoparticle for these lysine groups, meanwhile creating a binding interface complementary to the protein in size, shape, and distribution of acidic groups on the surface. These water-soluble nanoparticles possess excellent specificities for target proteins and sufficient affinities to inhibit natural PPIs such as those between cytochrome c (Cytc) and cytochrome c oxidase (CcO). With the ability to enter cells through a combination of energy-dependent and -independent pathways, they intervene apoptosis by inhibiting the PPI between Cytc and the apoptotic protease activating factor-1 (APAF1). Generality of the preparation and the excellent molecular recognition of the materials have the potential to make them powerful tools to probe protein functions in vitro and in cellulo.


Assuntos
Citocromos c , Complexo IV da Cadeia de Transporte de Elétrons , Nanopartículas , Polímeros , Nanopartículas/química , Citocromos c/metabolismo , Citocromos c/química , Humanos , Polímeros/química , Polímeros/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/química , Impressão Molecular/métodos , Ligação Proteica , Apoptose , Micelas , Células HeLa , Animais
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124357, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38692110

RESUMO

This study described the preparation of an azide covalent organic framework-embedded molecularly imprinted polymers (COFs(azide)@MIPs) platform for urea adsorption and indirect ethyl carbamate (EC) removal from Chinese yellow rice wine (Huangjiu). By modifying the pore surface of COFs using the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, COFs(azide) with a high fluorescence quantum yield and particular recognition ability were inventively produced. In order to selectively trap urea, the COFs(azide) were encased in an imprinted shell layer via imprinting technology. With a detection limit (LOD) of 0.016 µg L-1 (R2 = 0.9874), the COFs(azides)@MIPs demonstrated a good linear relationship with urea in the linear range of 0-5 µg L-1. Using real Huangjiu samples, the spiking recovery trials showed the viability of this sensing platform with recoveries ranging from 88.44 % to 109.26 % and an RSD of less than 3.40 %. The Huangjiu processing model system achieved 38.93 % EC reduction by COFs(azides)@MIPs. This research will open up new avenues for the treatment of health problems associated with fermented alcoholic beverages, particularly Huangjiu, while also capturing and removing hazards coming from food.


Assuntos
Polímeros Molecularmente Impressos , Ureia , Uretana , Vinho , Uretana/análise , Uretana/química , Polímeros Molecularmente Impressos/química , Ureia/análise , Ureia/química , Vinho/análise , Espectrometria de Fluorescência/métodos , Azidas/química , Limite de Detecção , Adsorção , Estruturas Metalorgânicas/química , Impressão Molecular/métodos
6.
Anal Biochem ; 691: 115551, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38702023

RESUMO

A molecularly imprinted electrochemical sensor was facilely fabricated for the detection of thymol (THY). o-Phenylenediamine (oPD) was used as the functional monomer and electropolymerized on the surface of the glassy carbon electrode (GCE) by using THY as the templates. After the THY templates were removed with 50 % (v/v) ethanol, imprinted cavities complementary to the templates were formed within the poly(o-phenylenediamine) (PoPD) films. The resultant molecularly imprinted PoPD/GCE (MI-PoPD/GCE) was used for the detection of THY, and a wide linear range from 0.5 to 100 µM with a low limit of detection (LOD) of 0.084 µM were obtained under the optimal conditions. The developed MI-PoPD/GCE also displays high selectivity, reproducibility and stability for THY detection. Finally, the content of THY in the real samples was accurately determined by the as-fabricated MI-PoPD/GCE, demonstrating its high practicability and reliability.


Assuntos
Técnicas Eletroquímicas , Impressão Molecular , Fenilenodiaminas , Timol , Fenilenodiaminas/química , Timol/análise , Timol/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Eletrodos , Polímeros Molecularmente Impressos/química , Carbono/química , Reprodutibilidade dos Testes
7.
J Chromatogr A ; 1725: 464876, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38718697

RESUMO

Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4-d-imprinted polymer (2,4-d-MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4-d-MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4-d-MIP (97.75 mg g-1) was considerably higher than those of phenoxyacetic acid (35.77 mg g-1), chlorogenic acid (9.72 mg g-1), spiramycin (1.56 mg g-1) and tylosin (1.67 mg g-1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers.


Assuntos
Ácido 2,4-Diclorofenoxiacético , Microesferas , Impressão Molecular , Água , Adsorção , Água/química , Ácido 2,4-Diclorofenoxiacético/análise , Ácido 2,4-Diclorofenoxiacético/química , Polímeros/química , Cinética , Polímeros Molecularmente Impressos/química
8.
Mikrochim Acta ; 191(5): 238, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38570401

RESUMO

Surface-enhanced Raman scattering (SERS) is a powerful method for detecting breast cancer-specific biomarkers due to its extraordinary enhancement effects obtained by localized surface plasmon resonance (LSPR) in metallic nanostructures at hotspots. In this research, gold nanostars (AuNSs) were used as SERS probes to detect a cancer biomarker at very low concentrations. To this end, we combined molecularly imprinted polymers (MIPs) as a detection layer with SERS for the detection of the biomarker CA 15-3 in point-of-care (PoC) analysis. This required two main steps: (i) the deposition of MIPs on a gold electrode, followed by a second step (ii) antibody binding with AuNSs containing a suitable Raman reporter to enhance Raman signaling (SERS). The MPan sensor was prepared by electropolymerization of the monomer aniline in the presence of CA 15-3. The template molecule was then extracted from the polymer using sodium dodecyl sulfate (SDS). In parallel, a control material was prepared in the absence of the protein (NPan). Surface modification for the control was performed using electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The performance of the sensor was evaluated using the SERS technique, in which the MPan sensor is first incubated with the protein and then exposed to the SERS probe. Under optimized conditions, the device showed a linear response to CA 15-3 concentrations from 0.016 to 248.51 U mL-1 in a PBS buffer at pH 7.4 in 1000-fold diluted serum. Overall, this approach demonstrates the potential of SERS as an optical reader and opens a new avenue for biosensing applications.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Neoplasias , Biomarcadores Tumorais , Impressão Molecular/métodos , Técnicas Biossensoriais/métodos , Anticorpos , Ouro/química
9.
Chemosphere ; 357: 141894, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615958

RESUMO

Given the presence of emerging pollutants at low concentrations in water bodies, which are inevitably affected by background substances during the removal process. In this study, we synthesized molecularly imprinted catalysts (Cu/Ni-MOFs@MIP) based on bimetallic metal-organic frameworks for the targeted degradation of ciprofloxacin (CIP) in advanced oxidation processes (AOPs). The electrostatic interaction and functional group binding of CIP with specific recognition sites on Cu/Ni-MOFs@MIP produced excellent selective recognition (Qmax was 14.82 mg g-1), which enabled the active radicals to approach and remove the contaminants faster. Electron paramagnetic resonance (EPR) analysis and quenching experiments revealed the coexistence of ∙OH, SO42-, and 1O2, with ∙OH dominating the system. Based on experimental and theoretical calculations, the reaction sites of CIP were predicted and the possible degradation pathways and mechanisms of Cu/Ni-MOFs@MIP/PMS systems were proposed. This study opens up a new platform for the targeted removal of target pollutants in AOPs.


Assuntos
Ciprofloxacina , Estruturas Metalorgânicas , Sulfatos , Poluentes Químicos da Água , Ciprofloxacina/química , Estruturas Metalorgânicas/química , Catálise , Poluentes Químicos da Água/química , Adsorção , Sulfatos/química , Impressão Molecular , Cobre/química , Oxirredução , Purificação da Água/métodos , Níquel/química
10.
J Hazard Mater ; 470: 134218, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38581878

RESUMO

The development of high-performance sensors for doxycycline (DOX) detection is necessary because its residue accumulation will cause serious harm to human health and the environment. Here, a novel tri-emission ratiometric fluorescence sensor was proposed by using "post-mixing" strategy of different emissions fluorescence molecularly imprinted polymers with salicylamide as dummy template (DMIPs). BSA was chosen as assistant functional monomer, and also acted as sensitizers for the aggregation-induced emission (AIE) effect of DOX. The blue-emitting carbon dots and the red-emitting CdTe quantum dots were separately introduced into DMIPs as the response signals. Upon DOX recognition within 2 min, blue and red fluorescence of the tri-emission DMIPs sensor were quenched while green fluorescence of DOX was enhanced, resulting in a wide range of color variations observed over bluish violet-rosered-light pink-orange-yellow-green with a detection limit of 0.061 µM. The sensor possessed highly selective recognition and was successfully applied to detect DOX in complicated real samples. Moreover, with the fluorescent color collection and data processing, the smartphone-assisted visual detection of the sensors showed satisfied sensitivity with low detection limit. This work provides great potential applications for rapid and visual detection of antibiotics in complex substrates.


Assuntos
Antibacterianos , Compostos de Cádmio , Doxiciclina , Impressão Molecular , Pontos Quânticos , Espectrometria de Fluorescência , Telúrio , Doxiciclina/análise , Doxiciclina/química , Pontos Quânticos/química , Telúrio/química , Antibacterianos/análise , Compostos de Cádmio/química , Limite de Detecção , Fluorescência , Carbono/química , Corantes Fluorescentes/química , Polímeros Molecularmente Impressos/química , Smartphone
11.
Food Chem ; 449: 139291, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38608609

RESUMO

The residues of erythromycin (ERY) may have negative impacts on the ecological environment, health, and food safety. How to detect ERY effectively and visually is a challenging issue. Herein, we synthesized a molecularly imprinted polymer based nanozymes for selective detection of erythromycin (ERY-MIPNs) at neutral pH, and developed a mobile phone-assisted bicolor colorimetric detection system. This system produced a wide range of color changes from blue to pinkish purple as the ERY concentration increased, making it easy to capture the visualization result. Also, the system showed good sensitivity to ERY ranging from 15 to 135 µM, with a detection limit of 1.78 µM. In addition, the system worked well in the detection of ERY in river water and milk, with the recoveries of 95.57% âˆ¼ 103.20%. These data suggests that this strategy is of considerable potential for practical applications and it provides a new idea for visual detection with portable measurement.


Assuntos
Colorimetria , Eritromicina , Leite , Rios , Poluentes Químicos da Água , Leite/química , Colorimetria/métodos , Animais , Rios/química , Eritromicina/análise , Eritromicina/isolamento & purificação , Poluentes Químicos da Água/análise , Telefone Celular , Impressão Molecular , Contaminação de Alimentos/análise , Limite de Detecção , Antibacterianos/análise , Polímeros Molecularmente Impressos/química
12.
Int J Biol Macromol ; 267(Pt 1): 131321, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38570001

RESUMO

The improper usage of levofloxacin (LEV) endangers both environmental safety and human public health. Therefore, trace analysis and detection of LEV have extraordinary significance. In this paper, a novel molecularly imprinted polymer (MIP) electrochemical sensor was developed for the specific determination of LEV by electrochemical polymerization of o-phenylenediamine (o-PD) using poly(3,4-ethylenedioxythiophene)/chitosan (PEDOT/CS) with a porous structure and rich functional groups as a carrier and LEV as a template molecule. The morphology, structure and properties of the modified materials were analyzed and studied. The result showed that the electron transfer rate and the electroactive strength of the electrode surface are greatly improved by the interconnection of PEDOT and CS. Meanwhile, PEDOT/CS was assembled by imprinting with o-PD through non-covalent bonding, which offered more specific recognition sites and a larger surface area for the detection of LEV and effectively attracted LEV through intermolecular association. Under the optimized conditions, MIP/PEDOT/CS/GCE showed good detection performance for LEV in a wide linear range of 0.0019- 1000 µM, with a limit of detection (LOD, S/N = 3) of 0.4 nM. Furthermore, the sensor has good stability and selectivity, and exhibits excellent capabilities in the microanalysis of various real samples.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Quitosana , Técnicas Eletroquímicas , Levofloxacino , Impressão Molecular , Polímeros Molecularmente Impressos , Polímeros , Quitosana/química , Levofloxacino/análise , Levofloxacino/química , Polímeros/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Impressão Molecular/métodos , Técnicas Eletroquímicas/métodos , Polímeros Molecularmente Impressos/química , Eletrodos , Limite de Detecção , Humanos
13.
Lab Chip ; 24(10): 2700-2711, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38651374

RESUMO

Mycotoxins are secondary metabolites of certain moulds, prevalent in 60-80% of food crops and many processed products but challenging to eliminate. Consuming mycotoxin-contaminated food and feed can lead to various adverse effects on humans and livestock. Therefore, testing mycotoxin residue levels is critical to ensure food safety. Gold standard analytical methods rely on liquid chromatography coupled with optical detectors or mass spectrometers, which are high-cost with limited capacity. This study reported the successful development of a microfluidic "lab-on-a-chip" device to enrich and detect zearalenone in food samples based on the fluorescence quenching effect of quantum dots and selective affinity of molecularly imprinted polymers (MIPs). The dummy template and functional polymer were synthesized and characterized, and the detailed microfluidic chip design and optimization of the flow conditions in the enrichment module were discussed. The device achieved an enrichment factor of 9.6 (±0.5) in 10 min to quantify zearalenone spiked in food with high recoveries (91-105%) at 1-10 mg kg-1, covering the concerned residue levels in the regulations. Each sample-to-answer test took only 20 min, involving 3 min of manual operation and no advanced equipment. This microfluidic device was mostly reusable, with a replaceable detection module compatible with fluorescence measurement using a handheld fluorometer. To our best knowledge, the reported device was the first application of an MIP-based microfluidic sensor for detecting mycotoxin in real food samples, providing a novel, rapid, portable, and cost-effective tool for monitoring mycotoxin contamination for food safety and security.


Assuntos
Contaminação de Alimentos , Dispositivos Lab-On-A-Chip , Polímeros Molecularmente Impressos , Pontos Quânticos , Zearalenona , Zearalenona/análise , Pontos Quânticos/química , Contaminação de Alimentos/análise , Polímeros Molecularmente Impressos/química , Impressão Molecular , Técnicas Analíticas Microfluídicas/instrumentação , Desenho de Equipamento , Análise de Alimentos/instrumentação
14.
J Chromatogr A ; 1722: 464859, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38604056

RESUMO

In this study, molecularly imprinted polymers (MIPs) were prepared for the specific recognition of organophosphorus pesticides and a rapid, efficient and simple method was established for the detection of dimethoate (DIT) in food samples. Fe3O4 magnetic nanoparticles were synthesized by co-precipitation, and Fe3O4/ZIF-8 complexes were prepared by a modified in-situ polymerization method, and then magnetic molecularly imprinted polymers (MMIPs) were prepared and synthetic route was optimized by applying density functional theory (DFT). The morphological characterization showed that the MMIPs were coarse porous spheres with an average particle size of 50 nm. The synthesized materials are highly selective for the organophosphorus pesticide dimethoate with an adsorption capacity of 461.50 mg·g-1 and are effective resistance to matrix effects. A novel method for the determination of DIT in cabbage was developed using the prepared MMIPs in combination with HPLC. The practical results showed that the method can meet the requirements for the determination of DIT in cabbage with recoveries of 85.6-121.1 % and detection limits of 0.033 µg·kg-1.


Assuntos
Brassica , Dimetoato , Limite de Detecção , Polímeros Molecularmente Impressos , Dimetoato/análise , Brassica/química , Polímeros Molecularmente Impressos/química , Adsorção , Cromatografia Líquida de Alta Pressão/métodos , Impressão Molecular/métodos , Nanopartículas de Magnetita/química , Extração em Fase Sólida/métodos , Contaminação de Alimentos/análise
15.
Opt Express ; 32(6): 10033-10045, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571224

RESUMO

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.


Assuntos
Impressão Molecular , Nanocompostos , Polímeros/química , Molibdênio , Tecnologia de Fibra Óptica
16.
Mikrochim Acta ; 191(4): 227, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558113

RESUMO

Chitosan, an abundant natural polysaccharide, was conjugated with carbon dots (CDs) and self-polymerized with chloramphenicol (CAP) templates to synthesize CD-incorporated and molecularly CAP-imprinted polychitosan (CD-MIC). The CD-MIC was used for fluorescent sensing, dispersive sorption, and dosage release of CAP at different pH levels. The sphere of action mechanism, approved by emission and excitation fluorescence, UV-Vis absorption, and fluorescence lifetime measurements, regulated the fluorescence static quenching. By the Perrin model, the quenching extent was linearly correlated to CAP within 0.17 - 33.2 µM (LOD = 37 nM) at pH 7.0. With an imprinting factor of 3.1, the CD-MIC was more selective for CAP than CD, although it was less sensitive to CAP. The recoveries of 5.0 µM CAP from milk matrix were 95% (RSD = 2.3%) for CD-MIC probes and 62% (RSD = 4.5%) for CD. The Langmuir and pseudo-second-order models preferably described the isothermal and kinetic sorptions of CAP into the imprinted cavities in CD-MICs, respectively. The Weber - Morris kinetic model showed three stages involved in intraparticle diffusion, which was pH-dependent and gradually arduous at the later stage, and showed external diffusion partly engaged in the diffusion mechanism. The 20 - 70% of CAP formulated in CAP-embedded CD-MICs were released in 8 - 48 h. The release percentage was lower at pH 7.0 than at pH 5.0 and 9.0, but the equilibrium time was shorter. At pH 7.0, the release percentage reached 45% at 10 min and slowly increased to 51% at 24 h.


Assuntos
Impressão Molecular , Pontos Quânticos , Carbono , Cloranfenicol , Portadores de Fármacos , Corantes
17.
Anal Methods ; 16(18): 2878-2887, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38639924

RESUMO

Shikimic acid (SA) is one of the most effective drugs against the A (H1N1) virus and has high medicinal value. Additionally, it has the ability to generate non-toxic herbicides and antimicrobial medications. The extraction from plants has proven to be the main route of production of SA with economic benefits and environmental efficiency. Therefore, it is necessary to perform purification of SA from these herbal medicines before quantifying it. In this study, researchers employed a boronate affinity-based controlled oriented surface imprinting technique to produce molecularly imprinted polymers (MIPs) as highly effective solid phase extraction (SPE) adsorbents for the isolation and purification of SA. 3-Fluoro-4-formylphenylboronic acid functionalized silica nanoparticles were used as supporting materials for immobilizing SA. Poly(2-anilinoethanol) with a higher hydrophilic domain can be used as an effective imprinting coating. The prepared SA-imprinted silica nanoparticles exhibited several significant results, such as good specificity, high binding capacity (39.06 ± 2.24 mg g-1), moderate binding constant (6.61 × 10-4 M-1), fast kinetics (8 min) and low binding pH (pH 5.0) toward SA. The replication of SA-imprinted silica nanoparticles was deemed satisfactory. The SA-imprinted silica nanoparticles could be still reused after seven adsorption-desorption cycles, which indicated high chemical stability. In addition, the recoveries of the proposed method for SA at three spiked level analysis in star aniseed and meadow cranesbill were 96.2% to 109.0% and 91.6% to 103.5%, respectively. The SA-imprinted silica nanoparticles that have been prepared are capable of identifying the target SA in real herbal medicines. Our approach makes sample pre-preparation simple, fast, selective and efficient.


Assuntos
Ácidos Borônicos , Impressão Molecular , Nanopartículas , Ácido Chiquímico , Dióxido de Silício , Extração em Fase Sólida , Dióxido de Silício/química , Nanopartículas/química , Impressão Molecular/métodos , Ácido Chiquímico/química , Ácido Chiquímico/isolamento & purificação , Ácidos Borônicos/química , Extração em Fase Sólida/métodos , Polímeros Molecularmente Impressos/química , Adsorção , Medicina Herbária/métodos
18.
Mikrochim Acta ; 191(5): 269, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630309

RESUMO

A molecularly-imprinted electrochemiluminescence sensor was constructed for the determination of fenpropathrin (FPT) by molecular imprinting technology. In this sensing platform, the introduction of CdS@MWCNTs significantly enhanced the initial ECL signal of the luminol-O2 system. Specifically, MWCNTs was used as a carrier to adsorb more CdS, in which CdS acted as a co-reaction promoter for luminescence. Molecularly imprinted polymer (MIP) containing specific recognition sites of FPT was used as the material for selective recognition. With increasing amount of FPT the ECL signal decreased. Under the optimum conditions, the ECL response was linearly related to the logarithm of FPT concentration. The developed ECL sensor allowed for sensitive determination of FPT and exhibited a wide linear range from 1.0 × 10- 10 mol L- 1 to 1.0 × 10- 6 mol L- 1. The limit of detection was 3.3 × 10- 11 mol L- 1 (S/N = 3). It can be used for the detection of FPT in vegetable samples.


Assuntos
Luminescência , Impressão Molecular , Piretrinas , Luminol , Polímeros Molecularmente Impressos
19.
Biosens Bioelectron ; 257: 116332, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38677016

RESUMO

In situ detection of dopamine (DA) at single-cell level is critical for exploring neurotransmitter-related biological processes and diseases. However, the low content of DA and a variety of distractors with similar oxidation potentials as DA in cells brought great challenges. Here, a sensitive and specific electrochemical nanosensor was proposed for in situ detection of DA in single living cells based on nanodiamond (ND) and molecularly imprinted polymer (MIP)-functionalized carbon fiber nanoelectrode (ND/MIP/CFNE). Due to its excellent electrocatalytic property, ND was modified to the surface of CFNE based on amide bonding. Compared with bare CFNE, ND-modified CFNE can enhance oxidation currents of DA by about 4-fold, improving signal-to-noise ratio and detection sensitivity. MIP was further electropolymerized on the surface of nanoelectrodes to achieve specific capture and recognition of DA, which could avoid the interference of complex matrix and analogs in cells. Taking advantage of the precise positioning capability of a single-cell analyzer and micromanipulator, ND/MIP/CFNE could be precisely inserted into different locations of single cells and monitor oxidation signal of DA. The concentration of DA in the cytoplasm of single pheochromocytoma (PC12) cell was measured to be about 0.4 µM, providing a sensitive and powerful method for single-cell detection. Furthermore, the nanoelectrodes can monitor the fluctuation of intracellular DA under drug stimulation, providing new ideas and methods for new drug development and efficacy evaluation.


Assuntos
Técnicas Biossensoriais , Dopamina , Técnicas Eletroquímicas , Polímeros Molecularmente Impressos , Análise de Célula Única , Dopamina/análise , Dopamina/química , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Células PC12 , Técnicas Eletroquímicas/métodos , Polímeros Molecularmente Impressos/química , Animais , Ratos , Nanodiamantes/química , Eletrodos , Fibra de Carbono/química , Impressão Molecular/métodos , Limite de Detecção , Polímeros/química
20.
J Agric Food Chem ; 72(18): 10655-10664, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38661642

RESUMO

Authenticating whole wheat foods poses a significant challenge for both the grain industry and consumers. Alkylresorcinols (ARs), serving as biomarkers of whole wheat, play a crucial role in assessing the authenticity of whole wheat foods. Herein, we introduce a novel molecularly imprinted electrochemical sensor with modifications involving a molecularly imprinted polymer (MIP) and MXene nanosheets, enabling highly sensitive and selective detection of ARs. Notably, we specifically chose 5-heneicosylresorcinol (AR21), the predominant homologue in whole wheat, as the template molecule. α-Cyclodextrin and acrylamide served as dual functional monomers, establishing a robust multiple interaction between the MIP and AR21. As a result, the sensor exhibited a wide linear range of 0.005 to 100 µg·mL-1 and a low detection limit of 2.52 ng·mL-1, demonstrating exceptional selectivity and stability. When applied to commercial whole wheat foods, the assay achieved satisfactory recoveries and accuracy, strongly validating the practicality and effectiveness of this analytical technique.


Assuntos
Técnicas Eletroquímicas , Contaminação de Alimentos , Impressão Molecular , Resorcinóis , Triticum , alfa-Ciclodextrinas , Resorcinóis/química , Resorcinóis/análise , Triticum/química , alfa-Ciclodextrinas/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Contaminação de Alimentos/análise , Limite de Detecção
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