Molecularly Imprinted Polymer Modified Electrode Prepared by In Situ Polymerization for Specific Determination of Norfloxacin

Abstract

Herein, a molecularly imprinted sensor was proposed via in situ polymerization technique for specifically sensing norfloxacin (NFX). The sensor indicates high stability due to the imprinting layer covalently conjugated on the surface of aminated glass carbon electrode. Emphasized, it shows excellent selectivity and specificity towards NFX ascribed to the unique characteristics of molecularly imprinted polymers (MIPs). Even in the presence of 10-fold concentration of its structural analog ciprofloxacin, there is no evident interference in the determination of NFX. Under optimized conditions, the oxidation current of square wave voltammetry (typically at +1.03 V vs Ag/AgCl) increases linearly with the concentration of NFX increasing in the ranges of 0.1–10 μM and 10−160 μM. And the limit of detection is 0.004 μM (based on a signal-to-noise ratio of 3). Average recoveries from (spiked) real water samples are between 99.63% and 103.20% with relative standard derivations less than 4.67% (n = 3) at three spiked levels, validated by independent assays of HPLC. This work provides a successful model for fast preparing MIP-based electrochemical sensors for detecting trace drug residues in environmental samples.