Real-Time Fiber Optic Sensor System for Monitoring Chemicals in Water

At a Glance

Researchers at Colorado State University have developed a compact and rugged fiber optic biosensor for detecting chemicals in water. The system can monitor several chemicals at different locations along the same fiber optic cable. It supports both continuous monitoring and on-demand measurements. Unlike traditional methods that require laboratory analysis, this device performs measurements directly in the field. The result is real-time chemical data without the need for added reagents.

Background

Measuring chemical levels in water systems in real time can be difficult. Most current methods require samples to be collected and analyzed in a laboratory. This process takes time and cannot easily track changes at multiple points in a system. Optical sensors offer a practical alternative because they can send signals over long distances with little noise. Fiber optic sensing systems make it possible to monitor chemical conditions directly in the field.

Overview

This technology uses a photoluminescence-based fiber optic sensing system to detect chemical analytes. The device uses a multiplexed measurement design that allows several sensors to operate on the same fiber optic cable. Optical sources and sensors can run individually, in groups, or all at once. Each sensing point sends its own measurement signal along the fiber. This allows users to monitor chemical concentrations at multiple locations within a pipeline, groundwater system, or treatment process.

The system also allows flexible measurement schedules. Some analytes can be tracked continuously while others are measured only when needed. For example, one contaminant could be monitored continuously in groundwater while another is measured after rainfall or other environmental events. The device can also perform measurements on demand. The sensor system is compact, durable, and designed for reliable use in field environments without added reagents or laboratory analysis.

Figure 1. Configurations for photoluminescence sensing. (a) In the simplest apparatus, light is not confined by fiber optics and the detector is positioned to not receive the transmitted or reflected excitation beam. (b) In a system where the excitation light and emitted photoluminescence travel in a common fiber optic, a dichroic mirror or beamsplitter separates reflected excitation from the emitted wavelengths by only reflecting the latter. (c) An alternative configuration employs bandpass filters and a fiber optic splitter to implement the respective dichroic mirror functions of lightpath combining and wavelength filtering.

Benefits

Real-time monitoring of chemical concentrations
Multiple sensing locations along a single fiber optic line
No chemical reagents required for measurement
Lower operating cost than traditional lab testing
Durable design for long-term field deployment
Flexible operation with continuous, scheduled, or on-demand sensing

Applications

Drinking water monitoring
Groundwater monitoring
Wastewater treatment monitoring
Agricultural water quality management
Environmental contamination tracking
Environmental remediation monitoring
Industrial water process monitoring
Food production quality control

Publications

K.F. Reardon, et al. (2009) “Environmental applications of photoluminescence-based biosensors.” Advances in Biochemical Engineering/Biotechnology. https://doi.org/10.1007/10_2008_51

Last Updated: April 2026

Opportunity

Available for Exclusive Licensing
TRL: 5

IP Status

US 8,455,844

Inventors

Kevin L. Lear
Sean Piper

Reference Number

09-070

Licensing Manager

Jessy McGowan
Jessy.McGowan@colostate.edu
970-491-7100