Peroxidase-AgAu hybrid nanocages as signal transducers for sensitive plasmonic colorimetric sensing†
In this work, we report a type of highly sensitive signal transducer – HRP-AgAu hybrid cages – for plasmonic colorimetric sensing which was constructed by functionalizing silver–gold nanocages (AgAu cages) with horseradish peroxidase (HRP). The high sensitivity of this signal transducer is ascribed to the fact that the immobilized HRP molecules on the AgAu cage surface can substantially promote the etching of Ag from the cages using H2O2 as an etchant, which induces sensitive multicolor changes. Compared to pristine AgAu cages, the HRP-AgAu hybrid cages were over 800 times more sensitive in response to H2O2. In addition to high sensitivity, the signal transducer features rapidity, simplicity, and visualization. Moreover, the signal transducer is compatible with the procedures and instruments of existing biosensing technologies, making it straightforward for practical applications. As a proof-of-concept demonstration, we applied the signal transducer in colorimetric sensing of glucose which showed a limit of detection as low as 0.5 μM.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry C HOT Papers