Publications by authors named "Feilang Zhao"

7 Publications

  • Page 1 of 1

An ultrasensitive and selective electrochemical sensor for determination of estrone 3-sulfate sodium salt based on molecularly imprinted polymer modified carbon paste electrode.

Anal Bioanal Chem 2017 Nov 9;409(27):6509-6519. Epub 2017 Sep 9.

School of Science, Harbin Institute of Technology, Shenzhen, Guangdong, 518055, China.

A highly sensitive and selective electrochemical sensor based on carbon paste electrode (CPE) modified with molecularly imprinted polymers (MIPs) has been developed for the determination of estrone 3-sulfate sodium salt (ESS). MIPs were prepared in polar medium via bulk polymerization and characterized by scanning electron microscopy and infrared spectroscopy. Cyclic voltammetry was performed to the study preparation process and binding behavior of the MIP-modified CPE (MIP/CPE) toward ESS. The conditions for preparing MIPs and MIP/CPE as well as ESS detection were optimized. Under the optimal experimental conditions, the detection linear range for ESS is 4 × 10 to 6 × 10 M with a limit of detection of 1.18 × 10 M (S/N = 3). In addition, the sensor exhibits high binding affinity toward ESS over its structural analogues with excellent repeatability and stability. The fabricated MIP/CPE was then successfully employed to detect ESS in pregnant mare urine (PMU) without any pretreatment, and the average recoveries were from 99.6 to 104.9% with relative standard deviation less than 3.0%. High-performance liquid chromatography was adopted as a reference to validate the established approach in detecting ESS and their results showed good agreement. The as-prepared sensor has high potential to be a decent tool for on-site determination of ESS in PMU in a fast and convenient manner. Graphical Abstract ᅟ.
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http://dx.doi.org/10.1007/s00216-017-0598-xDOI Listing
November 2017

Preparation of molecularly imprinted polymeric microspheres based on distillation-precipitation polymerization for an ultrasensitive electrochemical sensor.

Analyst 2017 Mar;142(7):1091-1098

School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China. and Key Laboratory of Xinjiang Phytomedicine Resources of Ministry of Education, School of Pharmacy, Shihezi University, Shihezi 832000, China.

A highly sensitive electrochemical sensor based on a carbon paste electrode (CPE) modified with molecularly imprinted polymeric microspheres (MIPMSs) was developed for the determination of bisphenol A (BPA). For the first time BPA-imprinted MIPMSs were prepared via distillation precipitation polymerization, and then the polymeric microspheres were involved in producing the MIPMS-modified CPE (MIPMS/CPE). The polymers obtained were observed via a scanning electron microscope and its dynamic and static adsorption performances were investigated. Cyclic voltammetry and electrochemical impedance spectroscopy were performed to study the preparation process and electrochemical behavior of the modified carbon paste electrodes with [Fe(CN)] ions acting as electrical indicators. Compared with the bulk MIP packed sensor, the MIPMS/CPE exhibits a higher sensing response and better reproducibility. The detection linear range for BPA is 1 × 10-1 × 10 M with a detection limit of 2.8 × 10 M (S/N = 3) under the optimal experimental conditions. Moreover, the MIPMS/CPE exhibited good selectivity and stability. The developed sensor can determine BPA in real samples including soil, milk and water rapidly and accurately after simple sample pretreatment.
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http://dx.doi.org/10.1039/c7an00059fDOI Listing
March 2017

Electrochemical microfluidic chip based on molecular imprinting technique applied for therapeutic drug monitoring.

Biosens Bioelectron 2017 May 19;91:714-720. Epub 2017 Jan 19.

College of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, China; Key Laboratory of Xinjiang Endemic Phytomedicine Resources, Ministry of Education, School of Pharmacy, Shihezi University, Shihezi, China. Electronic address:

In this work, a novel electrochemical detection platform was established by integrating molecularly imprinting technique with microfluidic chip and applied for trace measurement of three therapeutic drugs. The chip foundation is acrylic panel with designed grooves. In the detection cell of the chip, a Pt wire is used as the counter electrode and reference electrode, and a Au-Ag alloy microwire (NPAMW) with 3D nanoporous surface modified with electro-polymerized molecularly imprinted polymer (MIP) film as the working electrode. Detailed characterization of the chip and the working electrode was performed, and the properties were explored by cyclic voltammetry and electrochemical impedance spectroscopy. Two methods, respectively based on electrochemical catalysis and MIP/gate effect were employed for detecting warfarin sodium by using the prepared chip. The linearity of electrochemical catalysis method was in the range of 5×10-4×10M, which fails to meet clinical testing demand. By contrast, the linearity of gate effect was 2×10-4×10M with remarkably low detection limit of 8×10M (S/N=3), which is able to satisfy clinical assay. Then the system was applied for 24-h monitoring of drug concentration in plasma after administration of warfarin sodium in rabbit, and the corresponding pharmacokinetic parameters were obtained. In addition, the microfluidic chip was successfully adopted to analyze cyclophosphamide and carbamazepine, implying its good versatile ability. It is expected that this novel electrochemical microfluidic chip can act as a promising format for point-of-care testing via monitoring different analytes sensitively and conveniently.
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http://dx.doi.org/10.1016/j.bios.2017.01.037DOI Listing
May 2017

Pneumocandin B0-imprinted Polymer Using Surface-imprinting Technique for Efficient Purification of Crude Product.

Anal Sci 2016 ;32(9):923-30

Key Laboratory of Xinjiang Phytomedicine Resources for Ministry of Education, School of Pharmacy, Shihezi University.

In this work, we prepared surface molecularly imprinted polymer (MIP) for selective recognition of pneumocandin B0 (PNB0). Methacrylic acid (MAA) was first grafted onto silica gel particles (SiO2) in the manner of "grafting from" by using 3-methacryloxypropyl trimethoxysilane as intermedium, and then PNB0 molecules were imprinted on the surface of the obtained particles in the presence of ethylene glycol diglycidyl ether as the cross-linker. The prepared MIP-PMAA/SiO2 was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and thermo-gravimetric analysis, which confirmed the successful grafting of MAA onto SiO2 and the grafting degree was calculated to be 12.50 wt%. The binding properties of the products were investigated and it is found that the binding process of PNB0 followed the pseudo-second-order kinetic model. The as-prepared material also displays relatively quick adsorption kinetics and decent recognition affinity toward the template over its structurally related compound.
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http://dx.doi.org/10.2116/analsci.32.923DOI Listing
January 2018

Electrochemical sensor based on molecularly imprinted polymer for sensitive and selective determination of metronidazole via two different approaches.

Anal Bioanal Chem 2016 Jun 21;408(16):4287-95. Epub 2016 Apr 21.

Key Laboratory of Xinjiang Phytomedicine Resources for Ministry of Education, School of Pharmacy, Shihezi University, Shihezi, 832000, China.

A molecularly imprinted polymer decorated glassy carbon electrode (MIP/GCE) is facilely developed into an electrochemical sensing platform for detection of metronidazole (MNZ). MIP preparation was carried out via in situ electropolymerization and o-phenylenediamine was selected as the optimal functional monomer. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize and assess the performance of the so-obtained sensor. In particular, two assay methods, which are based on different principles, were involved in the detection procedure. One is based on MIP/catalysis (Method І) and the other is MIP/gate effect (Method II). Comparison of these two methods was made in the aspects including detection range, sensitivity, accuracy, selectivity, repeatability, and long-term stability. It is found that Method І affords a lower detection limit of 3.33 × 10(-10) M (S/N = 3) while the detection limit of Method II is 6.67 × 10(-10) M (S/N = 3). The linear range of Method І and II is 1.0 × 10(-9) to 1.0 × 10(-8) M and 2.0 × 10(-9) to 1.0 × 10(-7) M, respectively. The MIP/GCE exhibits good recognition ability towards the template molecule-MNZ in the presence of the analogues of MNZ and other interferents, which can be ascribed to the successful imprinting effect during MIP membrane preparation. Graphical Abstract Procedure for fabricating MIP/GCE and its application in detecting metronidazole in serum.
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http://dx.doi.org/10.1007/s00216-016-9520-1DOI Listing
June 2016

Preparation and characterization of erythromycin molecularly imprinted polymers based on distillation-precipitation polymerization.

J Sep Sci 2015 Sep 24;38(17):3103-9. Epub 2015 Jul 24.

School of Pharmacy, Xinjiang Medical University, Urumqi, Xinjiang, China.

Erythromycin-imprinted polymers with excellent recognition properties were prepared by an innovative strategy called distillation-precipitation polymerization. The interaction between erythromycin and methacrylic acid was studied by ultraviolet absorption spectroscopy, and the as-prepared materials were characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Moreover, their binding performances were evaluated in detail by static, kinetic and selective sorption tests. It was found that the molecularly imprinted polymers afforded good morphology, monodispersity, and high adsorption capacity when the fraction of the monomers was 7 vol% in the whole reaction system, and the adsorption data for imprinted polymers correlated well with the Langmuir model. The maximum capacity of the imprinted and the non-imprinted polymers for adsorbing erythromycin is 44.03 and 19.95 mg/g, respectively. The kinetic studies revealed that the adsorption process fitted a pseudo-second-order kinetic model. Furthermore, the imprinted polymers display higher affinity toward erythromycin, compared with its analogue roxithromycin.
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http://dx.doi.org/10.1002/jssc.201500448DOI Listing
September 2015

HPLC determination of diltiazem in human plasma and its application to pharmacokinetics in humans.

Biomed Chromatogr 2003 Dec;17(8):522-5

The Center of Medical Laboratory Science, Jinling Hospital, Clinical School of Medical College, Nanjing University, No. 305 East Zhongshan Road, Nanjing 210002, Jiangsu, People's Republic of China.

A simple and sensitive reversed-phase high performance liquid chromatographic method (HPLC) has been developed and validated for the routine analysis of diltiazem in human plasma and the study of the pharmacokinetics of the drug in the human body. Diltiazem and diazepa (internal standard) were extracted with a mixed organic solution of hexane, chloroform and isopropanol (60:40:5, v/v/v), and then HPLC separation of the drugs was performed on an Spherisorb C(18) column and detected by ultraviolet absorbance at 239 nm. The use of methanol-water solution (containing 2.8 mm triethylamine, 80:20, v/v) as the mobile phase at a fl ow-rate of 1.2 mL/min enables the baseline separation of the drugs free from interferences with isocratic elution. The method was linear in the clinical range 0-300 ng/mL and the lower limit of detection of diltiazem in plasma was 3 ng/mL. The range of percentage of relative standard deviation (%RSD) was from 3.5 to 6.8% for within-day analyses and from 6.2 to 8.4% for between-day analyses, respectively. The extraction recoveries of diltiazem from spiked human plasma (n = 5) at three concentrations were 91.4-104.0%. The method has been used to determine diltiazem in human plasma samples from eight volunteers who had taken diltiazem hydrochloride slow release tables and the data obtained was fitted with a program on computer to study the pharmacokinetics. The results showed that the peak level in plasma approximately averaged 118.5 +/- 14.3 ng/mL at 3.1 +/- 0.4 h, and the areas under the drug concentration curves (AUC) was 793.1 +/- 83.1 ng.h/mL.
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http://dx.doi.org/10.1002/bmc.270DOI Listing
December 2003