A library of bis[zinc(II)dipicolylamine]-functionalised linear peptides was prepared using an efficient solid phase peptide synthesis approach and their use as chemosensors for anions in water was investigated using indicator displacement assays. High affinity and selectivity for pyrophosphate (PPi) over adenosine triphosphate (ATP) and adenosine diphosphate (ADP) were observed and additional aromatic side chains provided enhanced discrimination between PPi and ATP.