Amperometric electrochemical sensor for chloramine detection in drinking water

Overview

This technology is an electrochemical amperometric sensor engineered to detect chloramines in drinking-quality water at concentrations below 100 ppb. Chloramines are commonly used as disinfectants in municipal water treatment, and accurate real-time monitoring is essential to ensure water safety while minimizing disinfectant byproducts. The sensor addresses the need for reliable, low-cost, and deployable water quality measurement by combining advanced nanomaterials with proven electrochemical detection principles.

The solution targets water utilities, environmental monitoring agencies, and industrial process operators who require continuous or remote monitoring of disinfectant residuals. Its miniaturizable form factor and simple instrumentation make it suitable for integration into distributed water quality monitoring networks, smart water infrastructure, and field-deployable testing platforms.

Technical specifications

Core detection principle:

• Chloramines (mono-, di-, and tri-chloramines) are electroactive species that undergo electrochemical reduction to ammonium and chloride ions via 2-, 4-, and 6-electron transfer processes, respectively.
• Amperometric detection measures the current generated during these reduction reactions, providing quantitative analysis of chloramine concentration.

Working electrode design:

• Carbon nanomaterials including carbon nanotubes, graphene, reduced graphene oxide, and diamond provide high surface area per unit volume and excellent electrochemical properties.
• Surface modification with conducting polymers (polyaniline, polypyrrole, polythiophene) and/or metal nanoparticles (platinum, gold, bismuth) enhances sensitivity, selectivity, and detection limits.
• This builds on prior demonstrated work using mercury film electrodes coated with conducting polymers and gold-nanoparticle-decorated polythiophene for chloramine detection.

Performance targets:

• Detection sensitivity below 100 ppb chloramine concentration
• High selectivity and accuracy in drinking-quality water matrices
• Robust operation suitable for continuous monitoring
• Compatible with both batch and flow-system configurations

System capabilities:

• Simple instrumentation requirements
• Miniaturizable design for portable or embedded deployment
• Suitable for in-line, autonomous, and remote measurement applications
• Interfaceable with electronics for automated data acquisition and transmission

Technology readiness level

The underlying amperometric sensor platform has been extensively validated by the research lab for detecting a wide range of analytes in water, including heavy metals, pesticides, sugars, organic and inorganic peroxides, and chemical warfare agents. These prior demonstrations in both batch and flow systems establish the technical foundation for the carbon nanomaterial-based electrode architecture.

Future validation activities will focus specifically on chloramine detection: fabricating working electrodes from carbon nanotubes, graphene, reduced graphene oxide, and diamond modified with conducting polymers or metal nanoparticles; optimizing operating conditions for sensitive, selective, accurate, and robust amperometric detection in drinking-quality water; and integrating the sensor into a flow system with electronic interfaces for in-line, autonomous, and remote chloramine monitoring. The technology is currently at an early-to-mid stage of development, with demonstrated platform capabilities but chloramine-specific validation and system integration remaining as next steps toward commercial readiness.