SouthWestSensor Ltd has developed a nanodroplet microfluidics based platform technology that brings lab analysis to the water. Perfectly suited for continuous monitoring of nutrients and pollutants in fresh and sea water, covering applications ranging from environmental monitoring to waste water process control.

Water sensing approaches over the years have mainly focused on optical or electrode based electrochemical approaches. While perfectly suited for some applications, considerable limitations still exist in terms of specificity and long-term performance. Wet chemistry based approaches as routinely used in testing labs can provide a solution, but often require frequent reagent change and extensive servicing. 

SouthWestSensor has developed a revolutionary approach that requires only minute volumes of liquid reagents to autonomously and quasi-continuously measure critical water parameters. The proprietary nanodroplet approach is the brain child of Dr. Xize Niu, SouthWestSensor’s Founder and also Associate Professor at the University of Southampton. ‘Nanodroplet microfluidics has been used in the lab for some time but typically requires significant instrumentation. We have pioneered a proprietary compact nanodroplet microfluidics format which is perfectly suited for in-the-field deployment. It’s exciting to start to see this translating into the commercial domain’. 

The developed nanodroplet based water sensor probe has already been tested for simultaneous monitoring of key water pollutants nitrite & nitrate. In a multi-week tidal river deployment, autonomously generated sensor data was found to be in excellent agreement with lab based measurement of grab samples (Environ. Sci. Technol.  2019, 53, 16, 9677-9685). The data quality is not surprising given that lab proven validated test chemistries are used, coupled with regular calibration with an on-device standard. Another advantage is that the nanodroplet platform approach lends itself to a rapid roll-out of additional tests. Following the initial nitrite & nitrate sensor launch, phosphate and ammonia sensors are already in the pipeline for launch in the first half of 2020. 

The water industry has taken note of this new approach, one with real disruptive potential. At the recent Aquatech Amsterdam 2019 exhibition, SouthWestSensor’s DropletSens-NO3 device was a finalist for the Innovation Award. Dr. Oliver Hofmann, SouthWestSensor CEO is leading the company’s early commercialisation efforts. ‘Microfluidic approaches all too often look promising on paper but fail to translate into commercial applications. SouthWestSensor has put in the required effort in terms of design and engineering to translate nanodroplet microfluidics into an effective and commercially viable solution for quasi-continuous sensing of critical water parameters. The key value proposition is a low-cost sensor device that autonomously produces high-frequency lab-quality data.  In our case this is achieved with reagent volumes that are orders of magnitude lower compared to our closest competitors. This critically translates into reduced maintenance requirements and underpins autonomous deployment for many weeks or even months.’

As lead users and early adopters, SouthWestSensor will be working with Environmental Agencies to use the device for nutrient and pollutant monitoring in lakes, rivers and the sea. Industrial target segments include fish farms, water utility and nutrient recovery companies, to name but a few. According to Dr. Hofmann ‘Providing high performance, low maintenance measurement tools is key for monitoring water quality and associated processes. With our high-frequency lab-quality data we hope to play a significant part in the drive towards digitisation of water quality. To this end we are currently looking for investors as well as commercial and strategic partners to maximise our reach and impact across the water industry’. 

It is hoped that this advanced sensing capability can help the water industry to optimise processes to better protect this ever more precious resource.