A Novel Controlled Release Immunosensor based on Benzimidazole Functionalized SiO2 and Cyclodextrin Functionalized Gold
Abstract
A novel controlled release system-based sandwich-type immunosensor is fabricated to detect squamous cell carcinoma antigen (SCCA). The 1-methyl-1H-benzimidazole functionalized mesoporous SiO2 (MBI-MS) is used to load methylene blue (MB). β-cyclodextrin functionalized gold (CD-Au) is introduced as the gatekeeper for encapsulating MB and capturing the adamantly functional detection antibody (ADA-Ab2). And pH stimulus serves as the trigger system to control the MB release. After the load of MB, the CD-Au blocks the pores of the MBI-MS by the host-guest interaction in the neutral condition. However, when the pH is below 7.0, CD-Au is separated from the surface of MBI-MS owing to the protonation of the aromatic amines. The encapsulated MB is released from the pores of MBI-MS and detected by square wave voltammetry. The controlled release immunosensor shows a relatively wide linear range from 0.001 to 20 ng·mL-1 with a low detection limit of 0.25 pg·mL-1. The immunosensor also shows good reproducibility and selectivity, which endows it broad application prospect in clinical research.
- Publication:
-
Scientific Reports
- Pub Date:
- January 2016
- DOI:
- 10.1038/srep19797
- Bibcode:
- 2016NatSR...619797M