Electrochemiluminescence Biosensor for Hyaluronidase Based on the Ru(bpy)32+ Doped SiO2 Nanoparticles Embedded in the Hydrogel Fabricated by Hyaluronic Acid and Polyethylenimine

Hyaluronidase (HAase), a specific enzyme of hyaluronic acid (HA), has been reported as a potential tumor biomarker in recent years. Hence, developing some simple, rapid, and sensitive methods for HAase assay is necessary. In this work, a simple and sensitive biosensor constructed by a reliable controlled release system and a mature electrochemiluminescence (ECL) analytical technique has been devised for the quantification of HAase with high efficiency and selectivity. Tris (2,2'-bipyridyl) ruthenium(II) chloride hexahydrate doped SiO₂ nanoparticles (Ru@SiO₂ NPs), as ECL signal probes, were trapped in the hydrogel fabricated by HA and polyethylenimine evenly and steadily. When HAase existed, the hydrogel was decomposed by HAase, and the Ru@SiO₂ NPs escaped from the hydrogel into the supernate. The ECL signal produced from the supernate can be detected and used to characterize HAase concentration. The result showed a good linear relationship between ECL intensity, and HAase concentration ranged from 2 to 60 U/mL and the limit of detection was 2 U/mL. The developed controlled release ECL biosensor has been used for HAase quantification in urine samples with satisfactory results.