Cellulose nanocrystals decorated with gold nanoparticles immobilizing GOx enzyme for non-invasive biosensing of human salivary glucose.
Cellulose nanocrystals (CNCs) material was converted into its dialdehyde before being decorated with gold nanoparticles (AuNPs) through an aminothiophenol linker. Then GOx enzyme was immobilized into the CNCs-AuNPs using thioctic acid (TA) as a double linker. The prepared materials were characterized using morphological (SPM & SEM) , spectroscopic (UV-Visible & FTIR) and electrochemical (CV & EIS) technniques. The GOx-TA-AuNPs-CNC developed material loaded onto GCE offered a convenient platform for developing a non-invasive enzymatic glucose biosensor for monitoring glucose in Human saliva. The designed biosensor demonstrated good analytical performance for glucose sensing using CV with a LR = 0.1 - 1.6 mM, R2 = 0.9925, and LOD = 40 µM at the physiological pH conditions. The developed biosensor possessed high selectivity towards the common glucose interferents like AA, UA and DA. The salivary glucose has been measured and correlated to the value of serum glucose of the same person samples.