Highly Protein-resistant AuNPs-ampholytes Modified Boric Acid Hydrogel for Saliva Glucose Detection

Saliva glucose detection using QCM technology has garnered significant attention of non-invasive blood glucose monitoring. Introducing antifouling materials is a pivotal strategy for addressing the issue of indiscriminate protein adsorption in saliva. Nonetheless, equipping surfaces with antifouling properties often comes at the cost of compromising the sensitivity of QCM tests. To tackle this challenge, we engineered an innovative antifouling hydrogel that integrates gold nanoparticles functionalized with L-cysteine (Au-Cys). When immobilized on quartz chips, this hydrogel not only enhanced glucose sensitivity but also significantly reduced nonspecific protein adsorption . The sensitivity of hydrogels without Au-Cys increased from 0.34 Hz/(mg/L) to 0.45 Hz/(mg/L) of hydrogels containing Au-Cys. Additionally, protein adhesion of bovine serum albumin, lysozyme, and mucin was markedly decreased by approximately 25, 10, and 50 times, respectively.