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Updated: Apr 15, 2026
Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors
Published on: September 10, 2013
Synthesis and characterization of pH-responsive and fluorescent poly (amidoamine) dendrimer-grafted cellulose
L Chen1, W Cao1, N Grishkewich1
1Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
Abstract:
Poly (amidoamine) (PAMAM) dendrimers have found promising applications in biomedicine and in the encapsulation of inorganic nanoparticles. G6 PAMAM dendrimer-grafted cellulose nanocrystals (CNC-PAMAM) were prepared via a simple carbodiimide-mediated amidation process and they displayed pH-responsive and fluorescent characteristics as confirmed by zeta potential, transmittance, isothermal titration calorimetry (ITC), and fluorescence spectroscopy. Stable aqueous dispersions of CNC-PAMAM were obtained at pH⩽4 and pH⩾10, driven by electrostatic repulsion from positive charge and negative charge respectively. However, large aggregates were formed at pH values from 5 to 9 due to electrostatic attraction. In addition, strong blue fluorescent emission was observed, and the fluorescent behaviour of CNC-PAMAM was influenced by the formation of aggregates. The pH-responsive and fluorescent properties of CNC-PAMAM may be suitable for their applications in pH-responsive nanodevices, fluorescent-based pH sensors, optical markers, and nanoreactors for the encapsulation of inorganic nanoparticles.
