Posttreatment of 3D‐printed surfaces for electrochemical applications: A critical review on proposed protocols

Abstract

This mini-review presents an overview of recent trends for 3D printed sensors and biosensors (with a focus on Fused Deposition Modeling (FDM) based technology), along with their posttreatment surfaces to improve electrochemical applications. The protocols described in the literature and advances in this field were covered, bringing a critical discussion about the achievements and limitations to improve the electrical properties of conducting filaments, as well as their electroanalytical performance. In addition, the pros and cons of the processes used in surface posttreatment to improve the performance of electrodes constructed by FDM are presented, comparing the time consumed during chemical and electrochemical treatments or combining the two to improve the characteristics of the sensors. Finally, the discussion about the real necessity of surface treatments of electrodes constructed by FDM technology, the techniques used for this, and some ecological protocols are discussed (surface posttreatments with and without reagents) or whether the simple optimization of printing parameters could also significantly improve the electrochemical performance of sensors built with such technologies.

The effect of water ingress on additively manufactured electrodes

“…In order to address this, in this paper we provide the first empirical study regarding the effects of water ingress on AMEs produced using FFF and the commonly used conductive filament, Protopasta (ProtoP). 6,15 More specifically, we demonstrate that over 28 days of immersion in water at room temperature, such AMEs can absorb sufficient water to cause changes in their electrochemical performance as assessed by cyclic voltammetry (CV). Overall, this work serves to demonstrate the importance of understanding polymer/solvent interactions for facilitating the further incorporation of polymer AM into the field of electrochemistry.…”

“…The majority of electrochemistry work using AMEs is carried out after a pre-activation step to remove surface polymer and reveal subsurface conductive carbon particles, which improves electrode performance. 15 Therefore, any part of the surface exposed to water ingress in most real applications is likely to be of this etched nature rather than pristine, as-printed polymer composite. To reflect this, activated ProtoP electrodes (labelled A-ProtoP) were generated by chronoamperometry in alkali solution, which has been established as an effective AME activation method.…”

Integrated multi-material portable 3D-printed platform for electrochemical detection of dopamine and glucose

“…[13][14][15][16] Additionally, several groups have also investigated how the anisotropy and orientation of the printed layers influence the electrochemical activity of 3Dprinted sensors, 11,12 as well as there have been multiple works on cleaning and surface activation protocols for optimized electrochemical performance. [16][17][18] These 3D-printing advances and optimizations have led several groups to develop novel electrochemical sensors to detect specific analytes. For example, the detection or quantification of commonly used redox species is widely demonstrated, covering both inner-and outer-sphere electron transfer reactions that show sensor performance and surface sensitivity.…”

“…13–16 Additionally, several groups have also investigated how the anisotropy and orientation of the printed layers influence the electrochemical activity of 3D-printed sensors, 11,12 as well as there have been multiple works on cleaning and surface activation protocols for optimized electrochemical performance. 16–18…”

New conductive filament ready-to-use for 3D-printing electrochemical (bio)sensors: Towards the detection of SARS-CoV-2

“…Activation procedures may cause the destruction or disintegration of the electrodes, are time-consuming, can generate chemical residues, and its performance depends on the polymeric composition of the filament (or 3D-printed device) [ 22 ]. In this aspect, the obtainment of a dispositive that brings the advantages of 3D printing, but provides satisfactory electrochemical responses without the need for surface pre-treatments, saving time and reagents expenditure (environmentally friendly), is emerged as very attractive.…”