Production of 3D-printed disposable electrochemical sensors for glucose detection using a conductive filament...

Three-dimensional printing techniques have been widely used in the fabrication of new materials applied to energy, sensing and electronics due to unique advantages, such as fast prototyping, reduced waste generation, and multiple fabrication designs. In this paper, the production of a conductive 3D-printing filament composed of Ni(OH)₂ microparticles and graphene within a polylactic acid matrix (Ni-G-PLA) is reported. The nanocomposite was characterized by thermogravimetric, energy-dispersive X-ray spectroscopic, scanning electronic microscopic, Raman spectroscopic and electrochemical techniques. Characteristics such as printability (using fused deposition modelling), electrical conductivity and mechanical stability of the polymer nanocomposite were evaluated before and after 3D printing. The novel 3D-printed disposable electrode was applied for selective detection of glucose (enzyme-less sensor) with a detection limit of 2.4 μmol L^-1, free from the interference of ascorbic acid, urea and uric acid, compounds typically found in biological samples. The sensor was assembled in a portable electrochemical system that enables fast (160 injection h^-1), precise (RSD < 5%) and selective determination of glucose without the need of enzymes (electrocatalytic properties of the Ni-G-PLA nanocomposite). The obtained results showed that Ni-G-PLA is a promising material for the production of disposable sensors for selective detection of glucose using a simple and low-cost 3D-printer.