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1.
In this study, molecularly imprinted polymer (MIP) was prepared and used in the preparation of carbon paste electrode (CPE) for the quantification of bisoprolol fumarate (BF) in pure, pharmaceutical formulation and biological fluids. The selective MIP for BF was synthesized from methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker in dimethyl sulfoxide solution, BF as the template molecule and 2, 2-azobisisobutyronitrile (AIBN) as the initiator. The non-imprinted polymer (NIP) was synthesized by the same procedure, but in the absence of the template molecule then incorporated in the paste of the carbon paste electrodes (CPEs). The prepared MIP for BF and its corresponding NIP were well characterized using scanning electron microscopy (SEM), Fourier transform infrared spectrometer, and thermal gravimetric analysis (TGA). The MIP and NIP based CPEs were further used for the determination of BF and the obtained results indicated that the sensor modified by the MIP have much higher recognition power for the BF molecules than the NIP based sensor where the MIP based CPE exhibited a Nernstian response 29.50±0.55 mV decade−1 within a concentration range of 1.0×10−7–1.0×10−2 mol L−1and pH independence in the range 3.50–7.15. The proposed sensor has high selectivity over several possible interfering compounds. The obtained results by the proposed sensor were satisfactory with excellent percentage recovery and relative standard deviation and were comparable with those obtained from HPLC reported method.  相似文献   

2.
Despite the increasing number of applications of molecularly imprinted polymers (MIPs) in analytical chemistry, the construction of a biomimetic potentiometric sensor remains still challenging. In this work, a biomimetic potentiometric sensor, based on a non‐covalent imprinted polymer was fabricated for the recognition and determination of cetirizine. The MIP was synthesized by precipitation polymerization, using cetirizine dihydrochloride as a template molecule, methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross linking agent. The sensor showed high selectivity and a sensitive response to the template in aqueous system. The MIP‐modified electrode exhibited Nernstian response (28.0±0.9 mV/decade) in a wide concentration range of 1.0×10?6 to 1.0×10?2 M with a lower detection limit of 7.0×10?7 M. The electrode has response time of ca. 20 s, high performance, high sensitivity, and good long term stability (more than 5 months). The method was satisfactory and used to the cetirizine assay in tablets and biological fluids.  相似文献   

3.
《Electroanalysis》2017,29(11):2579-2590
In this study, an electrochemical sensor was developed and used for selective determination of bisfenol‐A (BPA) by integrating sol‐gel technique and multi‐walled carbon nanotubes (MWCNTs) modified paste electrode. BPA bounded by covalently to isocyanatopropyl‐triethoxy silane (ICPTS) was synthesized as a new precursor (BPA‐ICPTS) and then BPA‐imprinted polymer (BPA‐IP) sol‐gel was prepared by using tetramethoxysilane (TMOS) and BPA‐ICPTS. Non‐imprinted polymer (NIP) sol‐gel was obtained by using TMOS and (3‐Aminopropyl) triethoxysilane. Both BPA‐IP and NIP sol‐gels were characterized by nitrogen adsorption‐desorption analysis, FTIR, SEM, particle size analyzer and optical microscope. Carbon paste sensor electrode was fabricated by mixing the newly synthesized BPA‐IP with MWCNTs, graphite powder and paraffin oil. The electrochemical characterization of the sensor electrode was achieved with cyclic and differential pulse voltammetric techniques. The response of the developed sensor under the most proper conditions was linear in BPA concentration range from 4.0×10−9 to 1.0×10−7 mol L−1 and 5.0×10−7 to 5.0×10−5 mol L−1 and the detection limit was 4.4×10−9 mol L−1. The results unclosed that the proposed sensor displayed high sensitivity and selectivity, superior electrochemical performance and rapid response to BPA.  相似文献   

4.
In this study, a molecularly imprinted electrochemical sensor (MIP/DA) was investigated for selective and sensitive determination of dopamine (DA) by electrochemical polymerization of p-aminothiophenol in the presence of DA on gold electrode. According to electrochemical behaviour of the sensor, gained through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), MIP/DA sensor showed distinctive electron transfer characteristics in comparison to the non-imprinted (NIP/DA) sensor. Besides the MIP/DA sensor showed high selectivity for dopamine through its analyte specific cavities. The sensor had a broad working range of 5.0×10−8–2.0×10−7 M with a limit of detection (LOD) of 1.8×10−8 M and the developed sensor was successfully applied for determination of dopamine in pharmaceutical samples.  相似文献   

5.
《Electroanalysis》2017,29(3):708-715
The wide use of pesticides can lead to environmental and human adverse effects. Diazinon, as an organophosphorous pesticide, is used in agriculture because of its low cost and high efficiency on insects. Due to the increasing application of pesticides, accurate analytical methods are necessary. The aim of this work was modification of carbon paste electrode composition and applying it as a sensor for determination of diazinon in biological and environmental samples. Multi‐walls carbon nanotubes and a molecularly imprinted polymer were used as modifiers in the sensor composition. A molecularly imprinted polymer and a non‐imprinted polymer were synthesized for applying in the electrode. After optimization of electrode composition, it was used to determine the analyte concentration. Instrumental parameters affecting the square wave voltammetric response were adjusted to obtain the highest current intensity. The modified electrode with MIP showed very high recognition ability compared to the electrode containing NIP. The obtained linear range was 5×10−10 to 1×10−6 mol L−1. The detection limit of the sensor was 1.3×10−10 mol L−1 and the relative standard deviation for analysis of target molecule by the proposed sensor was 2.87 %. This sensor was used to determine the diazinon in real samples (human urine, tap, and river water samples) without special sample preparation before analysis. The optimization of electrode composition containing mentioned modifiers improved its response considerably.  相似文献   

6.
An electrochemical sensor for amoxicillin (AMX) detection based on reduced graphene oxide (RGO), molecular imprinted overoxidized polypyrrole (MIOPPy) modified with gold nanoparticles (AuNPs) is described in this work. The electrochemical behavior of the imprinted and non‐imprinted polymer (NIP) was carried out by cyclic voltammetry (CV) and impedance spectroscopy (IS). The structure and morphology of the prepared MIP sensor were characterized by scanning electron microscopy (SEM), UV‐Visible, Fourier transform infrared spectroscopy (FTIR) and its experimental parameters such as monomer and template concentration, pH buffer solution, incubation time of AMX and AuNPs, scan rate as well as electropolymerization scan cycles were optimized to improve the performance of the sensor. The peak current obtained at the MIP electrode was proportional to the AMX concentration in the range from 10?8 to 10?3 mol L?1 with a detection limit and sensitivity of 1.22 10?6 mol L?1 (Signal to noise ratio=3) and 2.52×10?6 μAmol?1 L, respectively. It was also found that this sensor exhibited reproducibility and excellent selectivity against molecules with similar chemical structures. Besides, the analytical application of the AMX sensor confirms the feasibility of AMX detection in milk and human serum.  相似文献   

7.
We present a novel electrochemical sensor based on an electrode modified with molecularly imprinted polymers for the detection of chlorpyrifos. The modified electrode was constructed by the synthesis of molecularly imprinted polymers by a precipitation method then coated on a glassy carbon electrode. The surface morphology of the modified electrode was characterized by using field‐emission scanning electron microscopy and transmission electron microscopy. The performance of the imprinted sensor was thoroughly investigated by using cyclic voltammetry and differential pulse voltammetry. The imprinted electrochemical sensor displayed high repeatability, stability, and selectivity towards the template molecules. Under the optimal experimental conditions, the peak current response of the imprinted electrochemical sensor was linearly related to the concentration of chlorpyrifos over the range 1 × 10−10–1 × 10−5 mol/L with a limit of detection of 4.08 × 10−9 mol/L (signal‐to‐noise ratio = 3). Furthermore, the proposed molecularly imprinted electrochemical sensor was applied to the determination of chlorpyrifos in the complicated matrixes of real samples with satisfactory results. Therefore, the molecularly imprinted polymers based electrochemical sensor might provide a highly selective, rapid, and cost‐effective method for chlorpyrifos determination and related analysis.  相似文献   

8.
Miniaturized potentiometric membrane sensors for quinine incorporated with molecular imprinted polymer (MIP) were synthesized and implemented. Planar PVC based polymeric membrane sensors containing quinine‐methacrylic and/or acrylic acid‐ethylene glycol methacrylate were dispensed into anisotropically etched wells on polyimide wafers. The determination of quinine was carried out in acidic solution at pH 6, where positively charged species predominated prevalently. The suggested miniaturized planner sensors exhibited marked selectivity, sensitivity, long‐term stability and reproducibility. At their optimum conditions, the sensors displayed wide concentration ranges of 4.0×10?6–1.0×10?2mol L?1 and 1.0×10?5–1.0×10?2 mol L?1 with slopes of about 61.3–55.7 mV decade?1; respectively. Sensors exhibit detection limits of 1.2×10?6 and 8.2×10?6 mol L?1 upon the use of methacrylic and acrylic acid monomers in the imprinted polymer, respectively. Validation of the assay method according to the quality assurance standards (range, within‐day repeatability, between‐day variability, standard deviation, accuracy, and good performance characteristics) which could assure good reliable novel sensors for quinine estimation was justified. Application of the proposed flow‐through assay method for routine determination of quinine in soft drinks was assayed and the results compared favorably with data obtained by the standard fluorimetric method.  相似文献   

9.
This work proposes a novel biomimetic sensor for the potentiometric transduction of rivastigmine based on molecularly imprinted polymer (MIP). Using the Taguchi method, this study analyzed the optimum conditions for preparing the MIP‐based membranes. The rank order of each controllable factor was also determined. MIP‐based membranes exhibited a Nernstian response (30.7±1.1 mV decade?1) in a concentration range from 1.0×10?5 to 1.0×10?2 mol L?1 with a LOD of 6.3×10?6 mol L?1. The sensor was successfully applied to the determination of rivastigmine concentrations in human serum, plasma, urine, rat brain and tablets.  相似文献   

10.
《Electroanalysis》2017,29(2):566-577
Two novel carbon paste electrodes based on gentamicin‐reineckate (GNS‐RN)/multiwall carbon nanotubes (MWCNTs)/sodium tetraphenyl borate (NaTPB) or potassium tetraphenylborate (KTPB) for potentiometric determination of gentamicin sulfate were constructed. Our endeavors of lowering the detection limit for gentamicin ion‐selective electrodes were described. The paper focused on gentamicin carbon paste electrodes based on GNS‐RN as electroactive material, o ‐nitrophenyloctyl ether (o ‐NPOE) as plasticizer and incorporation of MWCNTs and lipophilic anionic additives (NaTPB and KTPB) which lower the detection limit of the electrodes showing best results for determination of gentamicin ion. The characteristics of the electrodes, GNS‐RN+NaTPB+MWCNTs (sensor 1) and GNS‐RN+KTPB+ MWCNTs (sensor 2), were measured, showing favorable features as they provided measurements of the potential with near‐Nernstian slopes of 29.6±0.3 and 29.1±0.3 mV/decade over the concentration range of 1.0×10−6–1.0×10−2 mol L−1 and pH ranges 3.0–8.2 and 3.0–8.0 in short response times (6.5 sec). Importantly, the electrodes had low detection limits of 3.0×10−7and 3.4×10−7 mol L−1 for the two sensors, respectively. The sensors showed high selectivity for gentamicin ion with respect to a large number of interfering species. The electrodes were successfully applied for the potentiometric determination of GNS ions in pure state, pharmaceutical preparations and human urine with high accuracy and precision. The results of this study were compared with some previously published data using other analytical methods.  相似文献   

11.
A molecularly imprinted polymer (MIP) sensor was successfully constructed on glassy carbon electrode for the determination of 1-naphthol (1-Nph). The sensor was constructed by electropolymerization on bare GCE in the presence of the target molecule. The recognition of 1-Nph was conducted indirectly using [Fe(CN)6]3−/4− as redox probe. The MIP sensor presented wide linear working range and limit of detection of 1.5×10−9 mol L−1. The MIP sensor was applied for the determination of 1-Nph in oilfield produced water. The results obtained showed good selectivity and sensitivity of the proposed sensor in terms of 1-Nph quantification.  相似文献   

12.
Two sensitive and selective potentiometric sensors based on zinc-iron layered double hydroxides/multiwalled carbon nanotubes (Zn−Fe LDH/MWCNTs) (sensor I) and graphene/multiwalled carbon nanotubes (Gr/MWCNTs) (sensor II) nanocomposites were developed for benzydamine hydrochloride (Benz) determination. The investigated sensors displayed excellent Nernstian slopes 58.5±0.7 and 59.5±0.5 mV decade−1, detection limits 8.3×10−7 and 1.9×10−7 mol L−1, long lifetimes, adequate selectivity, high chemical, and thermal stability within pH range of 2.4–8.5 for sensors І and ІІ, respectively. The surface morphology of sensors was analyzed using a Transmission Electron Microscope (TEM). The analytical method was efficiently implemented for Benz determination in biological fluids and surface water samples.  相似文献   

13.
A new molecularly imprinted polymer (MIP) was prepared using methamidophos (MAP) as the template molecule based on non‐covalent interaction. The complexes formed between template and monomers before polymerization were characterized by 1H NMR titration test, FT‐IR and UV spectrometry study. These studies indicated that a 1:2 molecular complex formed dominantly between MAP and functional monomers. A model mainly involving cooperative hydrogen interaction was proposed by exact placement of functional groups. Association constant was estimated to be 2.894 × 106 L2/mol2. When the initial concentration of MAP was 1.0 mmol L?1, the affinity capacity of MIP was 4.23 times that of NIP. The binding performance of MIP was modeled with the Freundlich isotherm (FI) and the total number of binding sites was calculated to be 33.97 μmol/g. The MIP showed great homogeneity with a heterogeneity index of m = 0.7356. The specificity of MIP was investigated by single‐analyte binding and molecularly imprinted solid‐phase extraction (MISPE) assays using MAP and other structurally related organophorous pesticides (OPPs). The results indicated that the MIP had a marked preference for MAP.  相似文献   

14.
We have developed a molecularly imprinted polymer (MIP) electrochemical sensor for entacapone (ETC) based on an electropolymerised polyphenylenediamine (Po-PD) on a glassy carbon electrode (GCE) surface. The direct electropolymerisation of the o-phenylenediamine monomer (o-PD) was carried out with ETC as a template. The steps of electropolymerization process, template removal and binding of the analyte were tested by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN)6]3−/[Fe(CN)6]4 − as a redox probe. The operation of the sensor has been investigated by differential pulse voltammetry (DPV). Under optimal experimental conditions, the response of the DPV was linearly proportional to the ETC concentration between 1.0×10−7 and 5.0×10−6 M ETC with a limit of detection (LOD) of 5.0×10−8 M. The developed sensor had excellent selectivity without detectable cross-reactivity for levodopa and carbidopa. The MIP sensor was successfully used to detect ETC in spiked human serum samples.  相似文献   

15.
A novel sensor for the determination of parathion‐methyl based on couple grafting of functional molecular imprinted polymers (MIPs) was fabricated which is developed by anchoring the MIP layer on surfaces of silica particles embedded CdSe quantum dots by surface imprinting technology. The synthesized molecular imprinted silica nanospheres (CdSe@SiO2@MIP) allow a high selectivity and sensitivity of parathion‐methyl via fluorescence intensity decreasing when the MIP material rebinding the parathion‐methyl molecule. Compared with the MIP fabricated in traditional method, the template of parathion‐methyl was easier to remove from the CdSe@SiO2@MIP imprinted material. Under optimal conditions, the fluorescence intensity of parathion‐methyl at the imprinted sensor was detected by spectrofluorophotometer. The relative fluorescence intensity of CdSe@SiO2@MIP decreased linearly with the increasing concentration of parathion‐methyl ranging from 0.013 mg·kg−1 to 2.63 mg·kg−1 with a detection limit (3δ) of 0.004 mg·kg−1 (S/N=3), which is lower than the MIP in tradition. The imprinted film sensor was applied to detect parathion‐methyl in vegetable samples without the interference of other organophosphate pesticides and showed a prosperous application in the field of food safety.  相似文献   

16.
《Electroanalysis》2018,30(2):320-327
A novel molecularly imprinted polymer (MIP) photoelectrochemical sensor was fabricated for the highly sensitive and selective detection of triclosan. The MIP photoelectrochemical sensor was fabricated using graphite‐like carbon nitride (g‐C3N4) and gold nanoparticles (AuNPs) as photoelectric materials. The MIP/g‐C3N4‐AuNPs sensor used photocurrent as the detection signal and was triggered by ultraviolet light (UV‐Light 365 nm). g‐C3N4‐AuNPs was immobilized on indium tin oxide electrodes to produce the photoelectrochemically responsive electrode of the MIP/g‐C3N4‐AuNPs sensor. A MIP layer of poly‐o‐phenylenediamine was electropolymerized on the g‐C3N4‐AuNPs‐modified electrode to act as the recognition element of the MIP/g‐C3N4‐AuNPs sensor and to enable the selective adsorption of triclosan to the sensor through specific binding. Under optimal experimental conditions, the designed MIP/g‐C3N4‐AuNPs sensor presented high sensitivity for triclosan with a linear range of 2×10−12 to 8×10−10 M and a limit of detection of 6.01×10−13 M. Moreover, the MIP/g‐C3N4‐AuNPs sensor showed excellent selectivity. The sensor had been successfully applied in the analysis of toothpaste samples.  相似文献   

17.
为了改善分子印迹传感器的灵敏度, 在四丁基高氯酸铵的支持电解质溶液中, 以甲基丙烯酸为功能单体, 马来松香丙烯酸乙二醇酯为交联剂在纳米氧化铜修饰过的玻碳电极上电聚合了一种苯巴比妥(PB)识别性能的分子印迹传感膜. 采用循环伏安(CV)法、差分脉冲伏安(DPV)法及交流阻抗(EIS)法对这种纳米氧化铜修饰过的印迹及非印迹电极的电化学性能进行了研究, 结果显示纳米氧化铜修饰过的印迹及非印迹电极的电化学性能完全不同. X射线衍射(XRD)证实纳米粒子为氧化铜. 采用扫描电镜(SEM)对纳米氧化铜修饰过的印迹传感器的形貌进行分析, 发现纳米氧化铜分散在电极表面, 改善了修饰印迹传感器的识别点. 差分脉冲伏安法(DPV)表明苯巴比妥的浓度在1.0×10-8-1.8×10-4 mol·L-1 范围内呈现良好的线性关系(线性相关系数R=0.9994); 检出限2.3×10-9 mol·L-1 (信噪比(S/N)=3). 研究结果表明纳米氧化铜修饰过的印迹传感器具有较高灵敏度及选择性. 此印迹传感器能用于实际样品中苯巴比妥的检测, 加标回收率在95.0%-102.5%.  相似文献   

18.
A biomimetic potentiometric field monitoring device was developed for the trace determination of phorate (O,O‐diethyl S‐ethyl thiomethyl phophorodithioate) in natural waters. The sensing element was fabricated by the inclusion of phorate imprinted polymer materials in the polyvinyl chloride (PVC) matrix. The sensor surface can be reused without conditioning unlike most other conventional sensors. Operational parameters such as amount and nature of plasticizers sensing material, pH and response time were optimized. The response characteristics of the non‐imprinted (NIPIM) and imprinted polymer inclusion membrane (IPIM) sensors for phorate were compared under optimum conditions. The IPIM sensor responds linearly to phorate in the concentration in the ranges 1×10?9 to 1×10?6 M and 1×10?6 to 1×10?5 M of different slopes with a detection limit of 1×10?9 M. The selectivity was tested with various common organophosphorous (OP) pesticides and herbicides. In addition to superior sensitivity and selectivity of IPIM over NIPIM‐based sensor, IPIM‐based phorate sensor was found to be stable for 3 months and can be used for more than 40 times without any loss in sensitivity. The applicability for analyzing ground, river and tap‐water samples was successfully demonstrated via recovery studies.  相似文献   

19.
QU  Yunhe  LIU  ye  ZHOU  Tianshu  SHI  Guoyue  JIN  Litong 《中国化学》2009,27(10):2043-2048
An electrochemical sensor was modified with multi‐wall carbon nanotubes (MWCNT) and molecularly imprinted polymer (MIP) material synthesized with acrylamide and ethylene glycol dimethacrylate (EGDMA) in the presence of 1,3‐dinitrobenzene (DNB) as the template molecule. The MWCNT and MIP layers were successively modified on the surface of a glassy carbon electrode (GCE), of which the MIP film works as an artificial receptor due to its specific molecular recognition sites. The MIP material was characterized by FT‐IR and electrochemical methods of square wave voltammetry (SWV). The interferences of other nitroaromatic compounds (NAC) such as 2,4,6‐trinitrotoluene (TNT), 1,3,5‐trinitrobenzene (TNB) and 2,4‐dinitrotoluene (DNT) to DNB were also investigated by the prepared MIP/MWCNT electrode. Compared with other traditional sensors, the MIP/MWCNT modified electrode shows good selectivity and sensitivity. In addition, the current responses to DNB are linear with the concentration ranging from 4.5×10?8 to 8.5×10?6 mol/L with the detection limits of 2.5×10?8 (?0.58 V) and 1.5×10?8 mol/L (?0.69 V) (S/N=3). The construction process of MIP/MWCNT modified electrode was also studied as well. All results indicate that the MIP/MWCNT modified electrode established an improving way for simple, fast and selective analysis of DNB.  相似文献   

20.
《Analytical letters》2012,45(18):2920-2932
ABSTRACT

A novel potentiometric sensor based on a molecular imprinted polymer was developed for the determination of shikimic acid in herbal medicine. The imprinted polymer was synthesized via bulk polymerization of the functional monomer in the presence of trimethylolpropane triacrylate as the cross-linker with 2,2′-azo-bisisobutyronitrile as the initiator and shikimic acid as the template. The sensing membrane was constructed by the inclusion of imprinted polymer in the polyvinyl chloride matrix. The effect of the identity of the imprinted polymer on the potentiometric response was observed. The optimal imprinted polyacrylamide was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The performance of the imprinted membrane based sensor, including the effects of pH, response time and selectivity coefficient, was investigated. The imprinted sensor exhibited a fast near-Nernstian response in the concentration range of 1?×?10?5 to 1?×?10?1?mol/L with a detection limit of 9?×?10?6?mol/L. The analytical performance of the sensor supported the direct determination of shikimic acid in herbs, and the obtained results were validated by ultraviolet-visible absorption spectrophotometry. Advantages of the potentiometric sensor include enhanced sensitivity, high selectivity, long-term stability and low-cost fabrication, suggesting the device offers promise for the analysis of Chinese herbal medicine.  相似文献   

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