Environmental context. The on-site and real-time detection of metal ions is important for environmental monitoring and risk assessment. For appropriate management decisions, it is necessary to specifically sense the labile fraction of metal rather than total metal. This study provides a proof-of-principle that the DNAzyme GR5 can be used to sense labile lead in natural waters containing dissolved organic matter. (Image credit: D. Scott Smith.)

Environmental context. Unprecedented modification of the global nitrogen cycle by human activity is strongly imprinted in UK lakes by the changing abundance of nitrogen isotopes found in layers of lake sediment. UK lakes in the last century have responded to this change depending on their location, particularly if they are remote and occur above ~300-m altitude. Historical sediment nitrogen isotope data illustrate the impact of variable N sources on UK lakes, from fossil fuel combustion, synthetic fertilisers, to land use change and wastewater.

This article belongs to the collection: Dedication to Prof. Edward Tipping.