Computational study and multivariate optimization of hydrochlorothiazide analysis using molecularly imprinted polymer electrochemical sensor based on carbon nanotube/polypyrrole film

Abstract

An electrochemical sensor was developed by modifying multi-walled carbon nanotubes-molecularly imprinted polymer onto a pencil graphite electrode (PGE). A computational approach was used to screening functional monomers and polymerization solvent for rational design of molecularly imprinted polymer (MIP). Based on computational results, pyrrole and ethanol were selected as functional monomer and polymerization solvent, respectively. The MIP film was fabricated by electropolymerization of pyrrole in the presence of hydrochlorothiazide (HCT) as template molecule after electrodepositing of carboxyl functionalized multi-walled carbon nanotubes onto the surface of pencil graphite electrode. A Plackett–Burman experimental design was used to evaluate the influence of several variables on the analytical response (current). Then, the significant parameters were optimized using a central composite design, simultaneously. Under the optimized conditions, the detection limit (3sb, n=7) was found to be 1.0×10−10M. The calibration curve showed two dynamic linear ranges including 9×10−10 to 1×10−5M and 1×10−5 to 1×10−2M with correlation coefficients (r2) of 0.9986 and 0.9921, respectively. The prepared sensor showed a suitable reproducibility (RSD % of 3.36, n=3) and regeneration capacity. The sensor showed good results for determination of HCT in serum and pharmaceutical samples.