Beyond bubbles: greener flow-based electroanalysis by an air-driven carrier

Abstract

To minimize environmental issues and operational costs, using air to manipulate analyte/sample movement within milli/micro-sized channels can be a fascinating feature for flow-based electrochemical systems. However, maintaining uniform flow and undisturbed measurements during air bubble formation exhibits a considerable challenge. Here, we present a dual-mode electrochemical detection system that enables the use of air-driven carriers for controlling discrete electrolytic analyte solution injections, ensuring that transient signals remain unaffected by air bubble formation or when dealing with real-world samples. The proposed system effectively addresses critical limitations, such as air bubble interference, analyte dilution issues, contamination risks at the working electrode, and channel clogging, thereby minimizing maintenance. Performance evaluations validate the system's robustness and the reproducibility of measurements, ensuring the maintenance of analyte concentration during transport within the channel. Additionally, it demonstrates superior performance compared to traditional liquid-flow methods by reducing sample volume, minimizing waste generation, and lowering operational costs. Thus, this paper highlights the advantages of air-driven solutions for controlled analyte/sample injections, emphasizing their potential for more environmentally friendly flow-based electroanalysis.