Designing and Using 3D-Printed Components That Allow Students To Fabricate Low-Cost, Adaptable, Disposable, and Reliable Ag/AgCl Reference Electrodes

Abstract

A reference electrode is an essential component of all three-electrode electrochemical measurements. Common commercial reference electrodes, including the saturated calomel electrode and Ag/AgCl reference electrode, are expensive with the former containing toxic mercury. Cheaper alternatives have been proposed including Ag/AgCl references made from pipets and test tubes. However, electrodes prepared in this way are difficult to work with and are limited by the size and shape of glass casings that are available. This paper proposes an in-house manufactured Ag/AgCl reference electrode that uses some 3D-printed components in the fabrication process. This electrode is cheap to manufacture ($5 vs $60–100 CAD for the commercial reference electrode), and the design can be quickly altered due to the 3D printer’s capabilities in rapidly printing new electrode shapes to suit different analysts’ needs. The lab-made reference electrodes demonstrated stability and consistency in peak potential measurements in the cyclic voltammetry (CV) experiments. In ferricyanide CV tests, the recorded differences in anodic and cathodic peak potential (ΔE p) values for the commercial reference electrode and both lab-made electrodes were 68 ± 9%, 70 ± 12%, and 69 ± 13%, respectively. For all tests, the results were statistically comparable with those of the commercial Ag/AgCl reference electrode.

Additive Manufacturable Materials for Electrochemical Biosensor Electrodes

“…Another example was illustrated where AM was involved in developing a cheaper alternative to the costly reference electrodes. [ 321 ]…”

“…Another example was illustrated where AM was involved in developing a cheaper alternative to the costly reference electrodes. [321] Forward-looking applications consider the potential integration of biosensors with wearable technologies, where AM was used to develop personalized casings. [322,323] It is worth remarking that personalized wearables, particularly form-fitting, may play a crucial part in improving patient acceptance and compliance.…”

“…Reproduced with permission. [310,311,321,327] Copyright 2017, Elsevier B.V.; Copyright 2018, MDPI; Copyright 2018, American Chemical Society; Copyright 2020, Springer Nature. B) An example of AM used to fabricated ECBs components for a smart phone.…”

Versatile 3D-Printed Micro-Reference Electrodes for Aqueous and Non-Aqueous Solutions

“…[17][18][19] A more recent approach demonstrates the preparation of customizable REs with 3D-printed housings. [20] However, the REs presented in that work are large and hence not suitable for the application in small cells. Besides, those REs are printed from acrylonitrile butadiene styrene (ABS) that is unstable in acidic electrolytes and similar to the approach of other groups, [21,22] agar plugs are used to seal the bottom part, which are prone to leakage depending on pore size and temperature.…”

3D printing lifts the lid on black box instruments

“…The use of additive manufacturing (3D printing) in educational contexts has grown exponentially in the past several years [1][2][3]. Within the educational community, 3D printing has two primary forms: usable laboratory equipment/experiments [4][5][6][7][8][9][10][11], and in-class demonstrations/models, including orbitals [12,13], surfaces [14,15], molecular models [16][17][18], biological molecules [19][20][21], and data visualization [22,23]. While numerous laboratory examples have demonstrated the analytical use of 3D printing in the educational laboratory, little work has been demonstrated in the literature for analytical educational aids.…”