Nanoparticles Amplified QCM Sensor for Enzyme Activity Evaluation

Abstract

ABSTRACTThis investigation introduces a new very simple and efficient approach for QCM sensor response amplification, developed for hydrolases activity determination. For this purpose, the QCM crystal surface was modified with nanoparticles loaded enzyme substrate. During the enzymatic substrate degradation, the heavier nanoparticles were also released from the sensitive layer together with the substrate degradation products. Nanoparticles removal resulted in QCM signal amplification due to the higher nanoparticles specific mass compared with the specific mass of the substrate.The suggested concept was successfully applied for creating of simple biosensing platforms for trypsin and lipase activity determination in real time using respectively SiO2 nanoparticles loaded olive oil and Ag nanoparticles loaded gelatin as enzyme substrates. Up to 10 times amplification of the QCM signal was reached applying the proposed approach compared with the common one.