Peptide Cross-Linked Poly(2-oxazoline) as a Sensor Material for the Detection of Proteases with a Quartz Crystal Microbalance

• Published in: Biomacromolecules
• Main Author: Ahmad N.; Colak B.; Gibbs M.J.; Zhang D.-W.; Gautrot J.E.; Watkinson M.; Becer C.R.; Krause S.
• Format: Article
• Language: English
• Published: American Chemical Society 2019
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85069294673&doi=10.1021%2facs.biomac.9b00245&partnerID=40&md5=e75d6df205f2a845e8fd6113c8c6a8a1

Inflammatory conditions are frequently accompanied by increased levels of active proteases, and there is rising interest in methods for their detection to monitor inflammation in a point of care setting. In this work, new sensor materials for disposable single-step protease biosensors based on poly(2-oxazoline) hydrogels cross-linked with a protease-specific cleavable peptide are described. The performance of the sensor material was assessed targeting the detection of matrix metalloproteinase-9 (MMP-9), a protease that has been shown to be an indicator of inflammation in multiple sclerosis and other inflammatory conditions. Films of the hydrogel were formed on gold-coated quartz crystals using thiol-ene click chemistry, and the cross-link density was optimized. The degradation rate of the hydrogel was monitored using a quartz crystal microbalance (QCM) and showed a strong dependence on the MMP-9 concentration. A concentration range of 0-160 nM of MMP-9 was investigated, and a lower limit of detection of 10 nM MMP-9 was determined. © 2019 American Chemical Society.