scholarly journals A Molecularly Imprinted Sol-Gel Electrochemical Sensor for Naloxone Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 631
Author(s):  
Narges Shaabani ◽  
Nora W. C. Chan ◽  
Abebaw B. Jemere
Keyword(s):  
Indium Tin Oxide ◽  
Sol Gel ◽  
Electrochemical Techniques ◽  
Electrochemical Determination ◽  
Multiwall Carbon Nanotube ◽  
Molecularly Imprinted ◽  
Gel Layer ◽  
Sensing Material ◽  
Relative Standard ◽  
Optimized Conditions

A molecularly imprinted sol-gel is reported for selective and sensitive electrochemical determination of the drug naloxone (NLX). The sensor was developed by combining molecular imprinting and sol-gel techniques and electrochemically grafting the sol solution onto a functionalized multiwall carbon nanotube modified indium-tin oxide (ITO) electrode. The sol-gel layer was obtained from acid catalyzed hydrolysis and condensation of a solution composed of triethoxyphenylsilane (TEPS) and tetraethoxysilane (TES). The fabrication, structure and properties of the sensing material were characterized via scanning electron microscopy, spectroscopy and electrochemical techniques. Parameters affecting the sensor’s performance were evaluated and optimized. A sensor fabricated under the optimized conditions responded linearly between 0.0 µM and 12 µM NLX, with a detection limit of 0.02 µM. The sensor also showed good run-to-run repeatability and batch-to-batch performance reproducibility with relative standard deviations (RSD) of 2.5–7.8% (n = 3) and 9.2% (n = 4), respectively. The developed sensor displayed excellent selectivity towards NLX compared to structurally similar compounds (codeine, fentanyl, naltrexone and noroxymorphone), and was successfully used to measure NLX in synthetic urine samples yielding recoveries greater than 88%.

scholarly journals Carbon Quantum Dots Encapsulated Molecularly Imprinted Fluorescence Quenching Particles for Sensitive Detection of Zearalenone in Corn Sample

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 438 ◽  
Author(s):  
Manyu Shao ◽  
Ming Yao ◽  
Sarah De Saeger ◽  
Liping Yan ◽  
Suquan Song
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Sol Gel ◽  
Carbon Quantum Dots ◽  
Detection Range ◽  
Molecularly Imprinted ◽  
Relative Standard ◽  
Sol Gel Process ◽  
One Step ◽  
Optimized Conditions

An eco-friendly and efficient one-step approach for the synthesis of carbon quantum dots (CDs) that encapsulated molecularly imprinted fluorescence quenching particles (MIFQP) and their application for the determination of zearalenone (ZEA) in a cereal sample are described in this study. CDs with high luminescence were first synthesized, and then encapsulated in the silica-based matrix through a non-hydrolytic sol-gel process. The resulting ZEA-imprinted particles exhibited not only an excellent specific molecular recognition of ZEA, but also good photostability and obvious template binding-induced fluorescence quenching. Under the optimized conditions, the fluorescence intensity of MIFQP was inversely proportional to the concentration of ZEA. By validation, the detection range of these fluorescence quenching materials for ZEA was between 0.02 and 1.0 mg L−1, and the detection limit was 0.02 mg L−1 (S/N = 3). Finally, the MIFQP sensor was successfully applied for ZEA determination in corn with recoveries from 78% to 105% and the relative standard deviation (RSD %) was lower than 20%, which suggests its potential in actual applications.

scholarly journals Sol-gel-derived titanium oxide–cerium oxide biocompatible nanocomposite film for urea sensor

2009 ◽  
Vol 24 (5) ◽  
pp. 1667-1673 ◽  
Author(s):  
Anees A. Ansari ◽  
G. Sumana ◽  
M.K. Pandey ◽  
B.D. Malhotra
Keyword(s):  
Titanium Oxide ◽  
Cerium Oxide ◽  
Indium Tin Oxide ◽  
Nanocomposite Film ◽  
Sol Gel ◽  
Electrochemical Techniques ◽  
Dip Coating ◽  
Atomic Force ◽  
Coating Method ◽  
Dip Coating Method

Sol-gel-derived biocompatible titanium oxide–cerium oxide (TiO2–CeO2) nanocomposite film was deposited onto indium tin oxide (ITO)-coated glass substrate by the dip-coating method. This nanobiocomposite film has been characterized using x-ray diffraction, Fourier transform infrared, atomic force microscope, and electrochemical techniques, respectively. The particle size of the TiO2–CeO2 nanobiocomposite film was found to be 23 nm. The urea biosensor fabricated by immobilizing mixed enzyme [urease (Urs) and glutamate dehydrogenase (GLDH)] on this nanobiocomposite showed a response time of 10 s, sensitivity as 0.9165 μAcm−2mM−1, detection limit of 0.166 μM, and negligible effect due to interferants uric acid, cholesterol, glucose, and ascorbic acid. The value of Michaelis–Menten constant (Km) estimated using Lineweaver–Burke plot as 4.8 mM indicated enhancement in the affinity and/or activity of enzyme attached to their nanobiocomposite. This bioelectrode retained 95% of enzyme activity after 6 months at 4 °C.

Electrochemical determination of mesalazine by using graphene oxide coated with a molecularly imprinted sol–gel

2016 ◽  
Vol 8 (43) ◽  
pp. 7780-7788 ◽  
Author(s):  
Songjin Kim ◽  
Ning Wang ◽  
Yijun Li ◽  
Xiwen He
Keyword(s):  
Graphene Oxide ◽  
Sol Gel ◽  
Electrochemical Determination ◽  
Molecularly Imprinted

Graphene oxide coated with a molecularly imprinted sol–gel for mesalazine determination.

scholarly journals Gut microbiota derived trimethylamine N-oxide (TMAO) detection through molecularly imprinted polymer based sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. B. V. S. Lakshmi ◽  
Amit K. Yadav ◽  
Neha Mehlawat ◽  
Rekha Jalandra ◽  
Pratima R. Solanki ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Health ◽  
Molecularly Imprinted Polymer ◽  
Indium Tin Oxide ◽  
Electrochemical Techniques ◽  
Chemical Oxidation ◽  
Body Fluids ◽  
Imprinted Polymer ◽  
Detection Range ◽  
Molecularly Imprinted

AbstractTrimethylamine N-oxide (TMAO), a microbiota-derived metabolite has been implicated in human health and disease. Its early detection in body fluids has been presumed to be significant in understanding the pathogenesis and treatment of many diseases. Hence, the development of reliable and rapid technologies for TMAO detection may augment our understanding of pathogenesis and diagnosis of diseases that TMAO has implicated. The present work is the first report on the development of a molecularly imprinted polymer (MIP) based electrochemical sensor for sensitive and selective detection of TMAO in body fluids. The MIP developed was based on the polypyrrole (PPy), which was synthesized via chemical oxidation polymerization method, with and without the presence of TMAO. The MIP, NIP and the non-sonicated polymer (PPy-TMAO) were separately deposited electrophoretically onto the hydrolyzed indium tin oxide (ITO) coated glasses. The chemical, morphological, and electrochemical behavior of MIP, non-imprinted polymer (NIP), and PPy-TMAO were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and electrochemical techniques. The detection response was recorded using differential pulse voltammetry (DPV), which revealed a decrease in the peak current with the increase in concentration of TMAO. The MIP sensor showed a dynamic detection range of 1–15 ppm with a sensitivity of 2.47 µA mL ppm−1 cm−2. The developed sensor is easy to construct and operate and is also highly selective to detect TMAO in body fluids such as urine. The present research provides a basis for innovative strategies to develop sensors based on MIP to detect other metabolites derived from gut microbiota that are implicated in human health and diseases.

Selective Optosensing of Aminoimidazo-Azaarenes (AIAs) by CdSe/ZnS Quantum Dots-Embedded Molecularly Imprinted Silica Gel

2020 ◽  
Vol 17 ◽  
Author(s):  
Dan Qiao ◽  
Qiliang Deng ◽  
Shuo Wang
Keyword(s):  
Quantum Dots ◽  
Silica Gel ◽  
Limit Of Detection ◽  
Mutagenic Activity ◽  
Low Cost ◽  
Sol Gel ◽  
Fish Fillet ◽  
Molecularly Imprinted ◽  
Relative Standard ◽  
Molecularly Imprinted Silica

Background: The approach for the determination of aminoimidazo-azaarenes (AIAs) is urgent required due to their mutagenic activity and potential carcinogenicity. For this purpose, a CdSe/ZnS quantum dots (CdSe/ZnS QDs) - embedded molecularly imprinted silica gel with high selectivity and sensitivity was successfully prepared and applied to analyze such target. Methods: Herein, CdSe/ZnS QDs acted as the fluorescent probe, and molecularly imprinted silica gel as recognition probe was synthesized on the surface of QDs via sol-gel method. 2-Aminobenzimidazole, which has a similar structure with AIAs, as well as low cost and low toxicity, was selected as the dummy template. Results: The material has a high imprinting factor (IF=6.15); the linear range of CdSe/ZnS@MIP as a fluorescent sensing material for AIAs is 0.5-20.0 μg L -1 with the limit of detection (LOD) of 0.25 μg L -1 (3σ/s). Moreover, the fluorescent materials have been further applied to determine AIAs in beef floss and grilled fish fillet with satisfactory recoveries (82.8-110.8 %), and the relative standard deviation (RSD) is < 5.5%. Conclusion: The proposed CdSe/ZnS QDs-embedded molecularly imprinted silica gel can be used to easily and selectively detect AIAs.

scholarly journals ITO/Poly(Aniline)/Sol-Gel Glass: An Optically Transparent, pH-Responsive Substrate for Supported Lipid Bilayers

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed Al-Obeidi ◽  
Chenhao Ge ◽  
Kristina S. Orosz ◽  
S. Scott Saavedra
Keyword(s):  
Lipid Bilayers ◽  
Indium Tin Oxide ◽  
Sol Gel ◽  
Pani Film ◽  
Ph Response ◽  
Ito Electrode ◽  
Gel Layer ◽  
Optically Transparent ◽  
Lipid Diffusion ◽  
Poly Aniline

Described here is fabrication of a pH-sensitive, optically transparent transducer composed of a planar indium-tin oxide (ITO) electrode overcoated with a poly(aniline) (PANI) thin film and a porous sol-gel layer. Adsorption of the PANI film renders the ITO electrode sensitive to pH, whereas the sol-gel spin-coated layer makes the upper surface compatible with fusion of phospholipid vesicles to form a planar supported lipid bilayer (PSLB). The response to changes in the pH of the buffer contacting the sol-gel/PANI/ITO electrode is pseudo-Nernstian with a slope of 52 mV/pH over a pH range of 4–9. Vesicle fusion forms a laterally continuous PSLB on the upper sol-gel surface that is fluid with a lateral lipid diffusion coefficient of 2.2 μm2/s measured by fluorescence recovery after photobleaching. Due to its lateral continuity and lack of defects, the PSLB blocks the pH response of the underlying electrode to changes in the pH of the overlying buffer. This architecture is simpler to fabricate than previously reported ITO electrodes derivatized for PSLB formation and should be useful for optical monitoring of proton transport across supported membranes derivatized with ionophores and ion channels.

scholarly journals A Novel Mesoporous Multi-Template Molecularly Imprinted Polymer for Selective Separation and Determination of Panax notoginseng Saponins Simultaneously in Biological Samples

2017 ◽  
Author(s):  
Chenghong Sun ◽  
Jinhua Wang ◽  
Jiaojiao Huang ◽  
Dandan Yao ◽  
Chong-Zhi Wang ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Biological Samples ◽  
High Performance ◽  
Solid Phase ◽  
Panax Notoginseng ◽  
Selective Separation ◽  
Molecularly Imprinted ◽  
Relative Standard ◽  
Optimized Conditions

The feasible, reliable and selective multi-template molecularly imprinted polymers (MT-MIPs) based on SBA-15 (SBA-15@MT-MIPs) for the selective separation and determination of the trace level of ginsenoside Rb1 (Rb1), ginsenoside Rg1 (Rg1) and notoginsenoside R1 (R1) (Panax notoginseng saponins, PNS) from biological samples were developed. The polymers were constructed by SBA-15 as support, Rb1, Rg1, R1 as multi-template, acrylamide (AM) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The new synthetic SBA-15@MT-MIPs were satisfactorily applied to solid-phase extraction (SPE) coupled with high performance liquid chromatography (HPLC) for the separation and determination of trace PNS in plasma samples. Under the optimized conditions, the limits of detection (LODs) and quantitation (LOQs) of the proposed method for Rb1, Rg1 and R1 were in the range of 0.63-0.75 ng mL-1 and 2.1-2.5 ng mL-1, respectively. The recoveries of R1, Rb1 and Rg1 were obtained between 93.4% and 104.3% with relative standard deviations (RSDs) in the range of 3.3-4.2%. All results show that the obtained SBA-15@MT-MIPs could be a promising prospect for the practical application in the selective separation and enrichment of trace PNS in the biological samples.

Controlled Release of Nafcillin Using Biocompatible “Dummy” Molecularly Imprinted Sol-Gel Nanospheres

2015 ◽  
Vol 15 (3) ◽  
pp. 262-270 ◽  
Author(s):  
T. Lopez ◽  
M.A. Francos ◽  
A. Gonzalez ◽  
M.E. Diaz-Garcia ◽  
R. Badia-Laino
Keyword(s):  
Controlled Release ◽  
Sol Gel ◽  
Molecularly Imprinted

scholarly journals A simple approach to prepare fluorescent molecularly imprinted nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Sol Gel ◽  
Silica Sol ◽  
Simple Approach ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Molecularly Imprinted Nanoparticles

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.

Selective electromembrane extraction and sensitive colorimetric detection of copper(II)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wajid Ali Khan ◽  
Muhammad Balal Arain ◽  
Hashmat Bibi ◽  
Mustafa Tuzen ◽  
Nasrullah Shah ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Colorimetric Detection ◽  
Environmental Water ◽  
Selective Extraction ◽  
Effective Parameters ◽  
Relative Standard ◽  
Electromembrane Extraction ◽  
Optimized Conditions ◽  
Donor Phase

AbstractIn this study, an extremely effective electromembrane extraction (EME) method was developed for the selective extraction of Cu(II) followed by Red-Green-Blue (RGB) detection. The effective parameters optimized for the extraction efficiency of EME include applied voltage, extraction time, supported liquid membrane (SLM) composition, pH of acceptor/donor phases, and stirring rate. Under optimized conditions, Cu(II) was extracted from a 3 mL aqueous donor phase to 8 µL of 100 mM HCl acceptor solution through 1-octanol SLM using an applied voltage of 50 V for 15 min. The proposed method provides a working range of 0.1–0.75 µg·mL−1 with 0.03 µg·mL−1 limit for detection. Finally, the developed technique was applied to different environmental water samples for monitoring environmental pollution. Obtained relative recoveries were within the range of 93–106%. The relative standard deviation (RSD) and enhancement factor (EF) were found to be ≤4.8% and 100 respectively. We hope that this method can be introduced for quantitative determination of Cu(II) as a fast, simple, portable, inexpensive, effective, and precise procedure.

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