Application of a Fully 3D Printed Carbon Electrode for the Double Potential Step Chronoamperometry Determination of 2,4-dinitrophenol in Environmental Water Samples

Daniel Steven Shaw¹Zuhayr Rymansaib²Pejman Iravani²Kevin C Honeychurch^3*

• ¹Statens Serum Institut, Copenhagen, Denmark
• ²University of Bath, Bath, United Kingdom
• ³University of the West of England, Bristol, United Kingdom

This study represents the first reported application of a fully 3D printed carbon nanofiber–graphite–polystyrene working electrode for the double potential step chronoamperometric determination of 2,4-dinitrophenol in an environmental water sample. Initial cyclic voltammetric investigations were undertaken to characterise the redox behaviour of 2,4-dinitrophenol over the pH range 2 to 8. During the initial negative scan, two reduction peaks were observed, attributed to the reduction of the two nitro groups to their respective hydroxylamines. On the subsequent positive scan, two oxidation peaks were detected, corresponding to the oxidation of the hydroxylamines formed during the initial negative scan. All peaks were found to be pH dependent over the range studied. Using a double potential step chronoamperometric approach (step 1 = -1.4 V; step 2 = +0.8 V), a calibration plot was constructed and found to be linear from 50 µM to 1.0 mM (R2= 0.9978) with a detection limit of 7.8 µM (based on a signal-to-noise ratio of 3). The method was evaluated by carrying out 2,4-dinitrophenol determinations on a fortified and unfortified environmental pond water sample. Using external calibration, a mean recovery of 106% was obtained with an associated coefficient of variation of 3.6% calculated for a concentration of 50 µM. The results show that these 3D printed electrodes are a promising alternative to electrodes fabricated using traditional materials and that reliable data may be obtained for 2,4-dinitrophenol in environmental water samples.