Copper Electrodes via 3D Printing and Laser Sintering Fabrication for Nonenzymatic Glucose Detection

Glucose is considered an important marker for medical and food applications. Usually, glucose quantification is performed using a copper wire electrode. However, considering the growing demand for point-of-need analyses, the fabrication of disposable sensors has become an emerging technology. This study reports on the fabrication of disposable copper electrodes by combining fusion deposition modeling (FDM) 3D printing and laser sintering (LS). A copper/polylactic acid plate was first printed using an FDM 3D printer. Subsequently, a specific surface area was precisely sintered using an infrared (IR) laser engraving machine, resulting in an electrically conductive copper film, as confirmed by voltammetry and scanning electron microscopy characterizations. The laser processing parameters were optimized considering sensor sensitivity for glucose oxidation through amperometric measurements. The best parameters included the 1.6 W laser power, 5 mm s^–1 scan rate, 12 mm height, and 0.1750 mm distance between the laser engraver’s beamlines. Under optimum experimental conditions, the electrodes showed a linear response from 0.5 to 7.5 mmol L^–1 glucose, with their analytical applicability further demonstrated for the analysis of oral rehydration solution samples. Therefore, this work presents a straightforward approach for fabricating disposable copper electrode surfaces, offering rapidity, versatility, and potential utility for sensing applications beyond glucose quantification.