A "signal-on" electrochemical sensor for the rapid hyaluronidase activity detection in biologics and urine samples

Hyaluronidase (HAase) is a clinically important glycosidase that functions both as a drug diffusion enhancer and a disease biomarker. The quantification of HAase activity in biopharmaceutical products has received limited attention and still relies on conventional methods. Furthermore, the rapid and accurate determination of HAase activity is of great significance for cancer diagnosis and could facilitate the development of non-invasive examination methods. These considerations highlight the urgent demand for developing novel, rapid and accurate strategies for detecting HAase activity.

In this work, we developed a "signal-on" electrochemical sensor based on an enzyme-responsive hydrogel for the sensitive and rapid detection of HAase activity. The sensor was constructed by crosslinking hyaluronic acid (HA) and polyethylenimine (PEI) to form a hydrogel that electrostatically encapsulates methylene blue (MB). HAase-triggered hydrogel degradation releases MB, generating a measurable current increase. The results demonstrated a strong linear relationship (R² = 0.9973) between the change in current and HAase activity within the range of 0.78-90 U/mL, with a limit of detection of 0.48 U/mL. The sensor exhibits good specificity, repeatability, and storage stability. Moreover, the sensor has been successfully applied to the analysis of biopharmaceutical products and human urine samples.

This facile electrochemical sensor is capable of addressing both drug quality control and disease monitoring. With rapid detection in just 15 min, it significantly improves the efficiency of drug quality evaluation and disease diagnosis. This innovative approach offers a promising tool for the quality evaluation of HAase pharmaceuticals and their diagnostic monitoring.