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A novel imprinted sol–gel electrochemical sensor for the determination of propyl gallate (PG) was developed based on a composite of graphene and single walled carbon nanotubes (GR-SWCNTs). It was fabricated by stepwise modifying GR-SWCNTs and molecularly imprinted polymers and stored in 0.10 mol L −1 phosphate buffer solution pH 6.0, which endowed the sensor good sensitivity and selective recognition towards template molecules. The morphology and specific adsorption capacity of the sensor was characterized by scanning electron microscope and electrochemical methods, respectively. Under the optimized conditions, a linear range of the sensor to PG was 8.0 × 10 −8 –2.6 × 10 −3 mol L −1 with a limit of detection of 5.0 × 10 −8 mol L −1 (S/N = 3). The sensor exhibited specificity and selectivity towards template molecules as well as excellent reproducibility, regeneration and stability. Furthermore, the sensor could be applied to determine PG in edible oils, instant noodles and cookies with satisfactory results. [ABSTRACT FROM AUTHOR]

Highlights: [•] A sensor was developed for melamine direct and selective detection in real samples. [•] The sensor displayed a selectivity towards melamine compared with other interferents. [•] The sensor showed a linear relationship between the signal and the melamine concentration. [Copyright &y& Elsevier]

A novel molecular imprinted polymer (MIP) based thermo-sensitive electrochemical sensor was fabricated by an electropolymerization method using N-isopropylacryamide and theophylline as the monomer and the template molecule, respectively. The [Fe(CN)6]3−/[Fe(CN)6]4−was used as an electrochemical probe to investigate the electrochemical behavior of the prepared sensor. The influence factors including electropolymerization cycles, the utilization of cross-linkers, and the extraction solution were investigated in detail. The sensor exhibited excellent thermo-sensitive behavior to environmental temperature stimuli and displayed a good recognition capacity for template molecules from its analogues. This approach may allow the application of this type of intelligent electrochemical sensor for stimulus-responsive recognition of template molecules. [ABSTRACT FROM AUTHOR]

Molecular imprinting and sol-gel technique were combined to develop a molecular imprinted polymer (MIP) based electrochemical sensor in this work. With the successive modification of multi-walled carbon nanotubes (MWNTs) and gold nanoparticles (GNPs), a modified glassy carbon electrode (GCE) was immersed in a sol-gel solution in the presence of paracetamol (PR) for the electropolymerization to fabricate an imprinted sensor. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) were employed to characterize the constructed sensor. The factors for the sensor preparation, the electropolymerization potential range, the monomer concentration, and the scan rate for the sensor preparation were optimized. The sensor displayed an excellent recognition capacity toward PR compared with other analogues. Additionally, the DPV peak current was linear to the PR concentration in the range from 8.0 × 10−8to 5.0 × 10−5 mol/L, with a detection limit of 4.0 × 10−8 mol/L. The prepared sensor also showed satisfactory reproducibility and regeneration capacity. [ABSTRACT FROM AUTHOR]

Abstract: A simple and efficient molecularly imprinted polymers (MIPs) based electrochemical sensor were proposed and prepared by electropolymerization of pyrrole in the presence of bovine hemoglobin (BHb) in an aqueous solution. The fabrication process of the sensor was characterized by differential pulse voltammetry and electrochemical impedance spectroscopy, in which [Fe(CN)6]3−/[Fe(CN)6]4− was used as an electrochemical active probe. The influence factors including electropolymerization cycles, scan rate, the concentration of pyrrole, and the extraction conditions were investigated in detailed. Under the optimized conditions, the experimental results showed that the MIPs based sensor possessed a fast rebinding dynamics and an excellent recognition capacity to BHb, compared to the other non-template proteins. Moreover, the prepared sensor also exhibited a dependent relationship between the concentration of template protein and peak current of [Fe(CN)6]3−/[Fe(CN)6]4−. [Copyright &y& Elsevier]