A catalytically active molecularly imprinted polymer that mimics peroxidase based on hemin: application to the determination of p-aminophenol.
Despite the increasing number of applications of molecularly imprinted polymers (MIP) in analytical chemistry, the synthesis of polymers with hemin introduced as the catalytic center to mimic the active site of peroxidase remains as a challenge. In the current work, a new type of molecularly imprinted polymer (MIP) was synthesized with 4-aminophenol (4-APh) as the template and two monomers: hemin, which acts as the catalytic center, and methacrylic acid (MAA), which is used to build the active sites. This work shows that MIP successfully mimics peroxidase. For this purpose, a flow injection analysis system coupled to an amperometric detector was investigated through multivariate analysis. The determination of 4-APh was not affected by the equimolar presence of structurally similar phenol compounds, including catechol, 4-chloro-3-methylphenol, 2-aminophenol, guaiachol, chloroguaiachol and 2-cresol, thus highlighting the good performance of the imprinted polymer. Under the optimized experimental conditions, an analytical curve covering a wide linear response range from 0.8 up to 500 micromol L(-1) (r > 0.999) was obtained, and the method gave satisfactory precisions (n = 8), as evaluated via the relative standard deviation (RSD), of 4.1 and 3.2% for solutions of 4-APh of 50 and 500 micromol L(-1), respectively. Recoveries of 96-111% from water samples (tap water and river water) spiked with 4-APh were achieved, thus illustrating the accuracy of the proposed system.
de Jesus Rodrigues Santos
Wilney
W
Departamento de Química Analítica, Instituto de Química, Universidade Estadual de Campinas, Campinas, SP 13084-971, Brazil.
Lima
Phabyanno Rodrigues
PR
Tarley
César Ricardo Teixeira
CR
Kubota
Lauro Tatsuo
LT
D000627:Aminophenols / Q000032:analysis* / Q000737:chemistry; D001665:Binding Sites; D040761:Biomimetic Materials / Q000138:chemical synthesis*; D002384:Catalysis; D004563:Electrochemistry; D006427:Hemin / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry*; D015394:Molecular Structure; D009195:Peroxidase / Q000737:chemistry / Q000378:metabolism*; D011108:Polymers / Q000138:chemical synthesis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
D000627:Aminophenols; D008689:Methacrylates; D011108:Polymers; C008384:methacrylic acid; D006427:Hemin; D009195:Peroxidase; C026729:4-aminophenol