Riassunto analitico
In this study an amperometric sensor based on molecularly imprinted polymer (MIP) was developed for the sensitive and selective detection of piperonal. The choice of the starting monomer was based on a computational approach to study the interactions between monomer and template. The MIP and NIP (non-imprinted polymer) films were electrochemically grown via cyclic voltammetry and chronoamperometry on a glassy carbon disk electrode (2 mm diameter) in a conventional three-electrodes cell. The optimization of several important parameters, monomer and template concentration and number of scan cycles, was accomplished using the design of experiment, specifically a face centred composite design with three factors, two levels and 5 centre points. The electrochemical measurements were performed with differential pulse voltammetry (DPV) where piperonal showed an oxidation peak at ≈ 1,2 V. A calibration was performed on voltammetric grown MIPs, showing a good correlation factor (R2 = 0,9868) but poor linearity range (0-100 μM) and fairly high limit of detection (7,72 µM). Poor reproducibility was found, probably due to fouling phenomena. The MIP was also grown galvanostatically, showing increased reproducibility (17,2%) and repeatability (3,9%).
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Abstract
In this study an amperometric sensor based on molecularly imprinted polymer (MIP) was developed for the sensitive and selective detection of piperonal. The choice of the starting monomer was based on a computational approach to study the interactions between monomer and template. The MIP and NIP (non-imprinted polymer) films were electrochemically grown via cyclic voltammetry and chronoamperometry on a glassy carbon disk electrode (2 mm diameter) in a conventional three-electrodes cell. The optimization of several important parameters, monomer and template concentration and number of scan cycles, was accomplished using the design of experiment, specifically a face centred composite design with three factors, two levels and 5 centre points. The electrochemical measurements were performed with differential pulse voltammetry (DPV) where piperonal showed an oxidation peak at ≈ 1,2 V. A calibration was performed on voltammetric grown MIPs, showing a good correlation factor (R2 = 0,9868) but poor linearity range (0-100 μM) and fairly high limit of detection (7,72 µM). Poor reproducibility was found, probably due to fouling phenomena. The MIP was also grown galvanostatically, showing increased reproducibility (17,2%) and repeatability (3,9%).
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