Electrochemical sensors based on biomimetic magnetic molecularly imprinted polymer for selective quantification of methyl green in environmental samples

• Published in: Materials Science & Engineering C 2019-10, Vol.103, p.109825-109825, Article 109825
• Main Authors: Khan, Sabir, Wong, Ademar, Zanoni, Maria Valnice Boldrin, Sotomayor, Maria Del Pilar Taboada
• Format: Article
• Language: English
• Subjects: Adsorption; Adsorptivity; Anodic stripping; Biomimetic Materials - chemistry; Biomimetics; Carbon; Chemical sensors; Computer applications; Computer simulation; Dyes; Electrochemical analysis; Electrochemical sensor; Electrochemical Techniques; Electrochemistry; Environmental analysis; Fabrication; Imprinted polymers; Kinetics; Magnetic Phenomena; Magnetic-MIP; Materials science; Methyl Green - analysis; Methyl green dye; Molecular Imprinting; Polymers; Rivers; Sensors; Water analysis; Water sampling
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2019.109825

A new biomimetic sensor was prepared on carbon paste with magnetic molecularly imprinted polymer (mag-MIP) for sensitive and selective detection of methyl green dye. The mag-MIP was synthesized using a functional monomer that was selected before by computational simulation. A mag-NIP (magnetic non-imprinted polymer) control material was also prepared for comparative purposes. Modeling adsorption studied revealed that the dye-polymer interface followed pseudo-first order kinetics and that maximum adsorption (Qm) of the dye on mag-MIP was 3.13 mg g−1, while the value for mag-NIP was 1.58 mg g−1. The selective material was used as a sensing spot in fabrication of an electrochemical sensor based on modified carbon paste. For electrochemical analysis, the best achievement of the sensor was acquire by tack together a paste with 6.7% (w/w) of mag-MIP and using square-wave adsorptive anodic stripping voltammetry (SWAdASV) in 0.1 mol L−1 phosphate buffer (pH 7.0), with an applied potential (Eappl) of 0.3 V vs. Ag|AgClsat during an adsorption time (Tads) of 120 s. The results were obtained under optimized conditions in which sensor provided a linear concentration range of methyl green from 9.9 × 10−8 to 1.8 × 10−6 mol L−1, with a limit of detection (LOD) of 1.0 × 10−8 mol L−1 and a satisfactory relative standard deviation (RSD) of 4.3% (n = 15). The proposed sensor was applying using two spiked river water samples, obtaining recoveries ranging from 93% to 103%. The proposed method exhibits excellent precision also high reliability and proved to be an alternative method for the quantification of methyl green in real samples. [Display omitted] •A biomimetic sensor based in a mag-MIP selective to methyl green dye.•The functional monomer was previously chosen by computational simulation.•The proposed sensor showed good precision and high reliability,•The sensor is an alternative method to quantify methyl green in real samples.