Interfacial interactions are key to the development of high-performance coatings such as conductive polymer layers on fibrous materials. In this work, we present an approach of strengthening the interaction by forming ionic bonds between cellulose fibres and the conductive polymer layer by introducing a sulfonate group on cellulose fibres. The ionic bonds are formed between anchored sulfonate group and the positively charged precursor 3,4-ethylenedioxythiophene (EDOT), followed by the deposition and polymerisation of poly(3,4-ethylenedioxythiophene):sulfate (PEDOT:SO4) on the fibrous substrate surface. The conductance of the PEDOT:SO4 coated substrate with anchored sulfonate groups coated may be 1.7 times higher compared to the conductance of the unmodified cellulose substrate depending on experimental conditions. EDX measurements confirm the presence of sulfur and a shift of zeta potential at lower pH supports the evidence of the anionic anchored groups on the fibre surface. Our study therefore provides a new way to enhance the affinity of fibrous cellulose materials towards polymer conductive coatings. Display omitted •Successful grafting of sodium 4-((4,6-dichloro-1,3,5-triazin-2-yl)amino)benzenesulfonate on cellulosic fibres.•Formation of ionic bonds between anchored sulphonate group and positively charged precursor 3,4-ethylenedioxythiophene.•Higher yield of deposition polymerisation of poly(3,4-ethylenedioxythiophene) on modified fibre substrate.