ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

One-step preparation of porous copper nanowires electrode for highly sensitive and stable amperometric detection of glyphosate

Sujittra Poorahong, Chongdee Thammakhet, and Panote Thavarungkul

Trace Analysis and Biosensor Research Centre

Abstract: A simple and sensitive amperometric method for the detection of glyphosate based on a porous copper nanowire electrode is presented. The porous nanowires were fabricated simply by a one-step electrodeposition using hydrogen bubbles generated during the deposition to produce pores. These porous nanowires provided a 1.4 times larger surface area than a porous copper film. After the fabrication process the porous copper nanowires can be applied directly as a working electrode with the same custom-built flow cell. The detection was carried out by measuring the oxidation signal of copper; this increased with the concentration of glyphosate due to dissolution of the copper from the electrode. Under optimal conditions, the responses of the sensor were linear between 0.010-5.0 μmol L⁻¹, with a limit of detection of 10.0 nmol L⁻¹ (S/N = 3). The large surface area of the electrode minimised the corrosion effect, as observed by the remarkably stable response (95 injections of 0.20 μmol L⁻¹ of glyphosate were possible). When applied in order to detect glyphosate in fresh fruit and vegetable samples, the concentrations were found in the range of non-detectable to (0.104 ± 0.005) μmol L⁻¹. These results indicated that the fabrication process can be used to produce a new form of working electrode for glyphosate detection.

Keywords: porous copper electrode – hydrogen evolution – glyphosate – electrochemical detection – Cu(II)-glyphosate complex

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0038

Chemical Papers 69 (3) 385–394 (2015)