Low cost, simple three dimensional electrochemical paper-based analytical device for determination of p-nitrophenol

We report here the fabrication and electrochemical characterization of a three-dimensional paper-based analytical device made from pencil (hard and soft) and paper as a low-cost, simple, easy-to-use device for p-nitrophenol analysis. The three-dimensional device integrates filtration and was fabricated from conventional printing paper patterned with a wax printer. A quick response code (QR) was added to the device to enable the user to rapidly assess p-nitrophenol information. The counter electrode was drawn on the paper while the working electrode consisted of a short section of graphite obtained from a pencil (30 x 0.3 mm). p-Nitrophenol was selected as the target analyte and basic parameters such as solution pH, buffer concentration, and pulse amplitude were optimized. Under optimized conditions (0.1 M acetate buffer, pH 4.0), a detection limit of 1.1 mu M was obtained. The devices showed high sensitivity and a linear range for p-nitrophenol, 10 to 200 mu M. The devices were employed to determine p-nitrophenol in water samples and the results showed recoveries ranging from 91.8 to 108.2%. (C) 2014 Elsevier Ltd. All rights reserved.