Recently, the Lancet reported that in 2015 water pollution was linked to 1.8 million deaths worldwide. Environmental security and food safety are major global concerns, on account of rapid industrialisation, urbanisation and the increasing number of potentially harmful pollutants. As one in nine people around the world does not have access to clean water, contaminant detection addresses United Nations Sustainable Development Goals, as well as the new, stricter European regulations on drinking water standards.
Contamination with human and veterinary antibiotics pose a serious global threat. Drugs can accumulate in animal-derived foods, such as milk and meat, and also lead to antibiotic resistance. According to the first global study of antibiotic contaminations in rivers, led by the University of York and presented in 2019:
- The most polluted rivers are in Bangladesh, Kenya, Ghana, Pakistan and Nigeria
- Antibiotic concentrations were found to be above safe limits in 8% of the European sites
- The Danube is the most polluted river in Europe. Researchers found traces of seven antibiotics surpassing the safety threshold
- The Thames and some of its tributaries were contaminated by a mixture of five antibiotics
Beyond antibiotics, contaminants found in tap water and industry wastewater include mercury and other metals, as well as different types of small molecules, such as pesticides, herbicides, toxins, dyes, antioxidants, hormones and allergens. Since low concentrations of these pollutants are known to cause significant health and environmental problems, sensitive instruments with low detection limits must be used.
Conventionally, analyses on food and environmental samples are carried out with chromatography, mass spectrometry, ultraviolet detection and readout methods based on fluorescence markers. These are time-consuming, laborious and expensive techniques that require skilled personnel. Biosensors – instruments that generate an electrical output proportional to the concentration of the analyte of interest – offer cheaper, portable tools, which can be used directly at the site of sampling and with little training.
-> We are working on an accessible, reliable instrument with high sensitivity for small molecules.
The majority of biosensors for environmental monitoring are based on antibody binding or enzymatic reactions, but recently the development of aptamer-based sensors has gained a lot of interest. Aptamers – oligonucleotides specific for a target analyte – targeting toxic or non-immunogenic molecules can be easier to develop than antibodies. They are cheap, reusable and thermally stable.
-> Our tool can be adapted to immobilise a wide range of sensing biomolecules, including nucleic acids. We are keen to test your aptamers with our sensors - get in touch!
Furthermore, some of the recent environmental biosensors are tested only with tap water or are not applicable to real environmental samples, taken directly from rivers and lakes.
-> We are striving to develop a useful sensor for real applications.
Which type of small molecules are you studying and which problems are you facing? Let us know!
References
Landrigan P.J., et al. (2018). The Lancet Commission on pollution and health. The Lancet 391.10119: 462-512.
Centers for Disease Control and Prevention (2021). Global WASH fast facts. Accessed 18 August. 2021.
Reuters (2021). EU to tighten pollution laws to clean up air and water. Accessed 18 August 2021.
University of York (2019). Antibiotics found in some of the world’s rivers exceed ‘safe’ levels, global study finds. Accessed 18 August 2021.
The Guardian (2019). World’s rivers ’awash with dangerous levels of antibiotics. Accessed 18 August 2021.
European Environment Agency (2018). Chemicals in European waters. Accessed 18 August 2021.
Justino C.I.L, Duarte A.C., and Rocha-Santos T.A.P. (2017). Recent progress in biosensors for environmental monitoring: a review. Sensors, 17.12: 2918.
McConnell E.M., Nguyen J., and Li Y. (2020). Aptamer-based biosensors for environmental monitoring. Frontiers in Chemistry, 8: 434.