A Lab on a Buoy to Monitor Ocean Pollutants


Researchers of the ICN2 NanoBiosensors and Bioanalytical Applications Group, led by Prof. Laura M. Lechuga, in collaboration with Lionix International company (The Netherlands), have developed a photonic nano-immunosensor platform for real-time and on-site monitoring of ocean pollutants. This stand-alone device, developed in the context of the H2020 project BRAAVOO, will allow faster and cheaper monitoring of the marine environment.

Some of the buoys that we are used to see in the water when we go to the seaside might become soon little floating labs. The quality of seas and oceans can now be monitored in real-time and on-site thanks to new advanced biosensors, which can be integrated into a portable and reliable analysis platform to be installed inside of a stand-alone buoy in the close future. Since the dumping of chemical and biological waste in the oceans is rapidly degrading the marine environment, early detection of pollutants in the water is crucial to controlling and limiting their dramatic impact on the ecosystem.

A photonic nano-immunosensor platform for the analysis of different types of contaminants has been developed by researchers of the ICN2 NanoBiosensors and Bioanalytical Applications Group, led by Prof. Laura M. Lechuga, in collaboration with Lionix International company (The Netherlands). This study was carried out within the framework of the Biosensors, Reporters and Algal Autonomous Vessels for Ocean Operation (BRAAVOO) EU project, with the aim to develop not only a highly sensitive nanophotonic device, but also the required microfluidic, optical and electrical modules to make it self-contained for on-site monitoring.

Biosensors identify compounds on the basis of the molecular interactions between the substance of interest (called analyte) and its specific bioreceptors. They are beneficial for environmental analysis thanks to their high sensitivity and selectivity, even when operating on real samples, which haven’t received any treatment or preparation prior to the examination. Photonic biosensors, in particular, offer excellent miniaturization capabilities and can be used for multiplexing and multi-sample analysis.

To identify the contaminants in the sample, most photonic biosensors use a physics mechanism called evanescent wave sensing. Specifically, in this project a multiplexed asymmetric Mach-Zehnder interferometer (aMZI) sensor was used and, in order to allow the simultaneous analysis of several pollutants, a novel four-channel polymeric microfluidic cell was developed. A dedicated electronic module was also designed, together with the required software and data processing system. The placing of all these components inside a stand-alone buoy is essential for taking the monitoring tools directly to the contaminated place, which results is saving cost and time.

The applicability of this biosensor platform to pollution monitoring has been proved by testing it on two compounds (the antibiotic Tetracycline and the antifouling paint booster biocide Irgarol 1051) whose impact on the marine environment is particularly serious. As a following step, experiments will be conducted on real samples delivered directly by the sampling system of the buoy.