Inkjet Printed 3D Gold Electrochemical Sensor on Shape Memory Polymer for Lead Detection

Abstract

This paper reports a simple, miniaturized, reusable, and disposable electrochemical sensor fabricated using inkjet printed (IP) additive manufacturing technology on shape memory polymer (SMP) for lead detection (detection limit 14.4 µg/L with 180 seconds deposition time). The sensor consists of an IP three electrodes cell with gold (Au) working electrode, gold counter electrode, and silver chloride (AgCl) reference electrode. After inkjet printing Ag electrodes, the AgCl reference electrode is fabricated by chlorinating the Ag electrode with sodium hypochlorite solution. Au working and counter electrodes are obtained by immersion gold plating on the sintered Ag electrodes. Sensor characterization and optimization are reported and analyzed with cyclic voltammetry (CV) oxidation reduction peaks. 3 mM of lead in 0.1 M HCl is used to observe and optimize the chemical sensing properties of the reported sensor. Inkjet printing on SMP has provided increased effective electrode surface area (19.37 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> - approximately increased by a factor of 3.63 compared to lateral surface dimension, which is only 4.19 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) for electrochemical sensing (lead detection) allowing the fabrication of miniaturized electrochemical sensors with increased sensitivity for their size.