Functional native disulfide bridging enables delivery of a potent, stable and targeted antibody-drug conjugate (ADC)Electronic supplementary information (ESI) available: 1H and 13C NMR spectra for all small molecules, SDS-PAGE gels for bioconjugates. See DOI: 10.1039/c5cc03557k

Herein we report the use of next generation maleimides (NGMs) for the construction of a potent antibody-drug conjugate (ADC) via functional disulfide bridging. The linker has excellent stability in blood serum and the ADC, armed with monomethyl auristatin E (MMAE), shows excellent potency and cancer cell selectivity in vitro . A next generation maleimide-ADC is shown to have excellent stability in blood serum, as well as high potency and selectivity in vitro .