Poly(diallyldimethylammonium chloride)–cellulose nanocrystals supported Au nanoparticles for nonenzymatic glucose sensing

Abstract

Poly(diallyldimethylammonium chloride)–cellulose nanocrystal (PDDA–CNC) supported Au nanohybrids were prepared by in situ deposition, via the self-assembly between negative Au precursor and positively charged functional groups of PDDA–CNC. The Au/PDDA–CNC nanohybrids were characterized for their structural properties and for glucose sensing. Characterization studies show that the synthesis protocol led to well distribution of Au nanoparticles with a mean particle size varying from 3.5 to 8.4 nm on the PDDA–CNC support matrix depending on the Au concentration. The 5Au/PDDA–CNCs (i.e., Au loading level of 5 wt%) exhibited the best glucose sensing ability with a low detection limit of 2.4 μM (S/N = 3), high sensitivity of 62.8 μA mM⁻¹ cm⁻², a linear detection range from 0.004 mM to 6.5 mM, which was ascribed to the moderate size and dispersity of the Au nanoparticles. Further investigation revealed that the 5Au/PDDA–CNC nanohybrids also showed high selectivity and stability. These results suggest a new utilization route of CNCs decorated with metal nanoparticles in electrochemical biosensing.