ESPotensio: A Low-Cost and Portable Potentiostat With Multi-Channel and Multi-Analysis Electrochemical Measurements

Abstract

Electrochemical method is often chosen to analyze various bio-chemical reactions due to its operation simplicity with versatile applications. Thus, for this purpose, the procurement of potentiostat, an electrochemical-based analysis instrument, also needs to focus on the low price, but maintaining its rich analysis features. In this paper, we designed a low-cost and portable potentiostat system based on the ESP32 microcontroller. Even with the low-cost system design, it supports various electrochemical measurement methods, i.e. cyclic voltammetry (CV), linear sweep voltammetry (LSV), square wave voltammetry (SWV), differential pulse voltammetry (DPV), normal pulse voltammetry (NPV), and the observation of electrochemical current against time based on chronoamperometry measurement method. The potentiostat performance was assessed by the electrochemical signal accuracy and errors. Furthermore, the measurements can also be carried out semi-parallelly within three measurement channels simultaneously. The results showed that it could produce voltammograms with an average accuracy of more than 90%, compared to the commercial Emstat Pico. Even though having this comprehensive and extensive electrochemical analysis, the cost of the total system realization could be downsized to only USD 21.4.

Differential pulsed voltammetry of Δ9‐Tetrahydrocannabinol (THC) on disposable screen‐printed carbon electrodes: A potential in‐field method to detect Δ9‐THC in saliva

“…While the data presented was collected under lab conditions, it can be applied in the field with relative simplicity by dipping a SPCE strip in a vial of collected oral fluid (diluted in a small amount of buffer) and testing with a portable potentiostat. Alternatively, a pre‐dried buffer coating could be adhered on top of the working electrode surface to dissolve upon contact with a saliva sample [25]. The proposed method has attractive features such as low cost, small sample size, and ease of use.…”