Sensitive Hyaluronidase Biosensor Based on Target-Responsive Hydrogel Using Electronic Balance as Readout

The development of simple but sensitive methods for hyaluronidase (HAase) detection has been paid a great deal of attention because HAase is a potential cancer marker. In this work, a novel system coupled with a controlled release system has been designed for HAase determination without complex analytical instruments and skilled technicians. Pt@SiO₂ nanoparticles (NPs), which can catalyze the breakdown of H₂O₂ into O₂ and H₂O, was embedded in the hydrogel constructed by polyethylenimine (PEI) and hyaluronic acid (HA). In the presence of HAase, the hydrogel was broken down as HAase can catalyze the degradation of HA and hence the Pt@SiO₂ NPs in the hydrogel was released. The released Pt@SiO₂ NPs mixed with H₂O₂ solution in a drainage device, and then O₂ was generated due to the decomposition of H₂O₂, resulting in an enhancement of pressure in the drainage device because of the low solubility of O₂. A certain amount of H₂O overflowed from the drainage device because the difference of the pressure between the inner and outer of the drainage device. The overflowed H₂O was collected by a tube, and its amount was easily measured by an electronic balance. The weight of the H₂O has a linear relationship with the HAase concentration in the range of 1-60 U/mL (120 min enzymatic hydrolysis time) and 0.2-10 U/mL (240 min enzymatic hydrolysis time). The developed system has been applied to detect the activity of HAase in urine samples with satisfied results.