Researchers at Ruhr-Universität Bochum have developed a new method to determine a local pH value near a specific site of a biomolecule. A reliable measurement with a pH meter is only been possible in a larger ensemble, or homogeneous bulk. The new procedure, which is based on terahertz spectroscopy, is described by the team from Resolv in the journal Angewandte Chemie International Edition, published online in advance on 6 November 2020.