Described herein are the preparation and use of novel bromo-phosphonomethylphenylalanine amino acid derivatives (BrPmp) and BrPmp-containing peptides as specific, irreversible protein tyrosine phosphatase inhibitors, which are suitable for application in peptide synthesis. These derivatives are particularly advantageous since their synthesis is both easy and scalable, and they are suitable for peptide synthesis. The BrPmp derivatives described herein can be appropriately protected to allow for solid phase peptide synthesis (SPPS) and incorporation into peptides for preparation of protein tyrosine phosphatase inhibitors and inhibitor libraries. The peptides and peptide libraries can be used to identify new protein tyrosine phosphatase specific sequences and profile protein tyrosine phosphatase activity in cell lysates, diagnostic samples and biopsy samples.