The TNTs described here are constructed using FMOC peptide synthesis chemistry. Synthesis of peptide nucleic acid-TNT peptide conjugates is relatively straightforward as PNA synthesis can be achieved using the same FMOC protection groups that are used in peptide synthesis (27) . This means that peptide TNT-PNA conjugates can be synthesized on the same resin in a continuous process. PNA is a useful analogue of DNA and is advantageous for this application due to its high specificity and its neutral backbone, which means that it does not require high concentrations of salt to hybridize making it highly compatible with mass-spectrometry-based detection methods (28) (29) (30) .