Pyranine labeled polymer nanoparticles as fluorescent markers for cell wall staining and imaging of movement within apoplast

[Display omitted] •Pyranine containing polymers for biological applications were obtained via controlled radical polymerization.•High fluorescence yields were detected for the nanosize structures of self-assemblies in aqueous solutions.•Plant cell wall staining was observed during experiments on Arabidobsis seedlings.•Diffusion studies of polymer nanoparticles through apoplast showed difference in penetration rate depending on plant organ. A new fluorescent initiator based on pyranine was synthesized and applied for synthesis of the water-soluble polymers by controlled radical polymerization. The fluorophore based polymethacrylates were dependent on chain content providing small nanoparticles in the range of 0.6–3.4 nm. Fluorescent properties corresponding to green light emission were verified by quantum yield and fluorescence intensity showing the influence of polymer type and solvent. 7-day-old seedlings of Arabidopsis thaliana Col-0 were used in analysis of the penetration/movement of fluorescent nanoparticles (FNPs) in roots and cotyledons. Obtained results showed that: i) the best fluorescent nanoparticles for biological studies appeared to be choline methacrylate containing polymer (HPTS-ChMA); ii) cell membrane is a barrier for FNPs and iii) HPTS-ChMA is efficient fluorescent marker of plant cell walls independently of plant organ.