3D-Integration of Printed Electrochemical Sensors in Pet Microfluidics for Biochemical Sensing

This paper presents a novel process for screen printed electrode fabrication, functionalization and integration in a polyethylene terephthalate (PET) fluidics system for electrochemical analysis. The innovative components utilized are: 1. 3D Through-Foil Vias (TFVs) for electrode connection, enabling simple liquid tight lamination of micro-fluidic channels; 2. Screen printed carbon and silver/silver chloride (Ag/AgCl) electrodes on 3D vias; and 3. PET fluidics with a fabrication process compatible with large-area manufacturing. A platform integrating an Ag/AgCl pseudo-reference and a glucose oxidase (GOx)-modified working electrode has been used for glucose sensing in the flexible fluidics system. Detection of small glucose concentrations between 100-400 μM through Cyclic Voltammetry (CV) is shown. The sensor shows linear response and good sensitivity of ~0.8 mA/(mM cm
²
). By changing the electrode coatings, the same technology can potentially be used for detecting multiple analytes in biofluids.