Characterization and Electrochemical Analysis of Microelectrodes and the Interface with a Fabricated 3D-Printed Microfluidic Chip in an Upper-Division Analytical Course

Abstract

This work explores the interface between 3D-printing, material sciences, and microfluidics with electrochemical detection in an undergraduate laboratory. This work includes a module for the characterization and electrochemical analysis of microelectrodes that spans 4 weeks (3 h per week). Laboratory exercises include the fabrication of a 3D-printed device, examination of 3D-printing techniques, scanning electron microscopy (SEM), and electrochemistry. This interdisciplinary curricula exposed students to the process of designing a functioning microfluidic device. Students began by designing the microfluidic chip with AutoDesk Inventor. To gain a better understanding of the microelectrodes utilized in a microfluidic system, students explored the surfaces of various microelectrodes with SEM. On the basis of the visualization of the microelectrodes with SEM, students formed a hypothesis on the impact of electrode surface area on the sensitivity and limit of detection. Cyclic voltammetry in a classical three-electrode system was used to experimentally examine the relationship between electrode surface area and sensitivity. The module concluded with the use of the fabricated 3D-printed chip and amperometry to develop a calibration curve and determination of an unknown concentration of analyte. This work highlights the integration of 3D-printing, SEM, microfluidics, and electrochemistry into the upper-level undergraduate curriculum.