Electrochemical Detection Techniques for Chlorine Monitoring

Electrochemical methods for chlorine monitoring exploit redox reactions of chlorine species at electrode surfaces to deliver rapid, reagent-free, in-line measurements of free and total residual chlorine. These techniques employ a range of electrode materials and architectures, from carbon-based composites and noble metal films to semiconductor microdevices, to achieve high sensitivity, selectivity and durability. Typical approaches include cyclic voltammetry, in which the electrode potential is swept to characterise oxidation and reduction peaks of hypochlorite and hypochlorous acid, and amperometric detection, where a constant potential yields a current proportional to chlorine concentration. Advances in microfabrication and materials chemistry have yielded self-cleaning sensors resistant to fouling, pH-tunable electrode arrays that convert mixed chlorine species into a single detectable form, and composite electrodes that reduce interference from co-existing ions. Modern devices can be deployed in drinking-water distribution networks, ballast-water treatment systems and seawater applications, offering low detection limits down to micromolar levels and fast response times. Continuous online monitoring supports real-time control of disinfection processes, minimises disinfection by-products and enhances operational safety across municipal and industrial water supplies.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Electrochemical Detection Techniques for Chlorine Monitoring publication trend

The graph below shows the total number of articles in electrochemical detection techniques for chlorine monitoring across all publications each year (not limited to Nature Index journals).

Technical terms

Amperometry: Measurement of current at a fixed potential, proportional to analyte concentration.

Cyclic voltammetry: Potential swept cyclically at an electrode to characterise oxidation and reduction peaks.

Boron-doped diamond (BDD) electrode: Robust carbon electrode with a wide potential window and anti-fouling properties.

Limit of detection (LOD): Lowest analyte concentration that can be reliably distinguished from background noise.

Graphite–epoxy composite electrode: Carbon-based electrode material combining graphite with epoxy resin for enhanced stability and selectivity.

Reference electrode: Electrode with a stable and known potential used to control and measure the working electrode potential.

References

1. Indirect determination of free chlorine in seawater by cyclic voltammetry using graphite–epoxy composite electrode: Hydrogen adsorption capacity of graphite–epoxy composite is one–third of that of platinum. Sensing and Bio-Sensing Research (2024).
2. Electrochemical detection of free-chlorine in Water samples facilitated by in-situ pH control using interdigitated microelectrodes. Sensors and Actuators B Chemical (2020).
3. Potentiometric Sensor Based on Carbon Paste Electrode for Monitoring Total Residual Chlorine in Electrolytically-Treated Ballast Water. Sensors (2021).
4. A batch microfabrication of a self-cleaning, ultradurable electrochemical sensor employing a BDD film for the online monitoring of free chlorine in tap water. Microsystems & Nanoengineering (2022).