Material Design of a Chromium Imprinted Polymer and its Application as a Highly Selective Electrochemical Sensor for Determining Chromium Ion at Trace Levels
Majid Kalate Bojdi, Mohammad Behbahani, Zahra Baharian Feyzabadi
Abstract
Abstract This study investigates the development of a Cr (VI)‐selective electrode based on Cr (VI) imprinted polymer nanoparticles and its application in detection of chromium ions by differential pulse voltammetry. In methanol, precipitation polymerization of meta‐acrylate acid (the functional monomer), 2, 2′‐azobisisobutyronitrile (the initiator), ethylene glycol dimethacrylate (the cross‐linker), 1, 5‐Diphenylcarbazide (the chromium‐binding ligand), and chromium ions (the template ion) produced IP‐NPs. After polymerization, Cr (VI) was leached out from the polymer nanoparticles using NaOH/EDTA 0.5/0.1 mol L −1 to create holes for Cr(VI). After sorption of Cr (VI) ions and reduction to metallic shape, the detection method of differential pulse stripping voltammetry was performed on a carbon paste electrode modified with IP‐NPs. The response of electrodes modified with IP‐NPs differed significantly from that of electrodes modified with non‐IP‐NPs. The modified electrode reacts to Cr (VI) linearly in the 0.1 nM to 10.0 nM range with sensitivity of 0.9594 nA/nM and linearly in the 10.0 nM to 100.0 nM range with sensitivity of 0.1958 μA/μM. At signal to noise of 3, the sensor‘s method detection limit was 30 pM. The sensor was employed to detect Cr (VI) traces in ambient water samples that had been contaminated.