Homogeneous electrochemiluminescence biosensor for hyaluronidase based on the regulation of hyaluronic acid coating on magnetic nanoparticles

Abstract

A homogeneous electrochemiluminescence (ECL) sensor for hyaluronidase (HAase) detection was developed by controlling the coating of hyaluronic acid (HA) on the surface of magnetic ECL nanoparticles (NPs). Initially, Fe3O4@Ru@SiO2 NPs with magnetic properties were synthesized and subsequently coated with HA (Fe3O4@Ru@SiO2-HA). The properties of HA, such as its negative charge and viscosity, induced strong electrostatic repulsion and reduced electron transfer efficiency between the Fe3O4@Ru@SiO2-HA NPs and the negatively charged electrodes. Furthermore, this coating hindered the approach of co-reactants to the NPs, resulting in a diminished ECL signal. In the presence of HAase, HA is hydrolyzed, releasing the Fe3O4@Ru@SiO2 NPs. Magnetic separation minimizes background interference and allows the magnetic ECL NPs to diffuse freely in solution, facilitating electron transfer and reactant interaction, thereby leading to detectable signal changes. The sensor exhibited a linear response to HAase concentration ranging from 5.0 to 60 U/mL, with a detection limit of 1.8 U/mL. This method is rapid, straightforward, and effectively leverages the inherent properties of HA, making it suitable for broad applications in the detection of proteins, enzymes, and other biomarkers.