More than 783 million people worldwide are currently without access to clean and safe water. Approximately 1 in 5 cases of mortality due to waterborne diseases involve children, and over 1.5 million cases of waterborne disease occur every year. In the developing world, this makes waterborne diseases the second highest cause of mortality. Such cases of waterborne disease are thought to be caused by poor sanitation, water infrastructure, public knowledge, and lack of suitable water monitoring systems. Conventional laboratory-based techniques are inadequate for effective on-site water quality monitoring purposes. This is due to their need for excessive equipment, operational complexity, lack of affordability, and long sample collection to data analysis times. In this review, we discuss the conventional techniques used in modern-day water quality testing. We discuss the future challenges of water quality testing in the developing world and how conventional techniques fall short of these challenges. Finally, we discuss the development of electrochemical biosensors and current research on the integration of these devices with microfluidic components to develop truly integrated, portable, simple to use and cost-effective devices for use by local environmental agencies, NGOs, and local communities in low-resource settings.

During the recent pandemic outbreak, Lab-on-Chip devices did not manage to fully reach their potential in rapid diagnosis of pathogens, mainly due to the lack of cost-effective LoC solutions integrated with all required sample preparation modules. This paper presents such a critical step, aiming to translate electrochemical pH control into practical protein preconcentration modules, easy to integrate with subsequent quantification modules seamlessly via Lab-on-PCB technology. In this work we present a device capable of electrochemically controlling the pH of a solution local to an individually addressed electrode in a PCB array. The electrodes were functionalised with an electropolymerised self-assembled monolayer of 4-Aminothiophenol and were subjected to voltages of 0.2–0.4 V, evaluating for the first time the bias effect both over time and over space. This study enables for the first time the implementation of this technique for electrochemical pH control into practical Lab-on-PCB devices such as isoelectric focusing, via the informed design of such electrode arrays of appropriate size and spacing.

Protein preconcentration is an essential sample preparation step when analysing samples where the targeted proteins are in low concentrations, such as bodily fluids as well as water or wastewater. Nonetheless, very few practical implementations of miniaturized protein pre-concentration devices have been demonstrated in practice and even fewer in integration with other microanalytical steps. In this paper we propose for the first time a miniaturized isoelectric focusing-based protein-preconcentration device based on electrochemically derived pH gradients, rather than existing chemical reagent approaches. That way we are reducing the need for additional chemical reagents to zero, whilst enabling the device incorporation in a seamlessly integrated full protein analysis microsystem via Lab-on-PCB technology. We apply our previously presented Lab-on-PCB approach to quantitatively control the pH of a solution at the vicinity of planar electrodes using the electrochemical generation of acid through redox-active self-assembled monolayers. The presented device was comprised of a printed circuit board with an array of gold electrodes which was functionalised with 4-Aminothiophenol; this formed a self-assembled monolayer which was electropolymerised to improve its electrochemical reversibility. Protein preconcentration was performed in two configurations, one of which was open and required the use of a holder to suspend a well of fluid above the electrodes, and another which used microfluidic channels to enclose small volumes of fluid. Reported here is the data for protein preconcentration in both these forms with a quantitative concentration factor shown for the open form and qualitative proof shown for the microfluidic.