A colorimetric biosensor composed of split aptamers and mannan oligosaccharide nanozyme to monitor synthetic His-tagged food biomolecules.

Food synthetic biology is garnering increasing attention for its potential to generate bioactive components. His-tag is one of the most popular tags used in food synthetic biology. Herein, His-tag, His-tagged proteins, and His-tagged peptides were adopted as the model targets, and a commonly used biosensor was developed to monitor His-tagged food biomolecules, using split aptamers as specific recognition probes and nanozyme as the transduction element. A strategy to generate high-affinity split aptamers was proposed, obtaining a pair of split aptamers for His-tag (K _d  = 132 nM). AuNPs-mannan oligosaccharide nanozyme was fabricated and combined with the split aptamers to develop the biosensor. The functional mechanism of the probes and the nanozyme was revealed. The biosensor demonstrated good sensitivity, selectivity, and practicability when analyzing synthetic His-tagged proteins and peptides in real-world samples, with a limit of detection of 12.44 nM. The strategies provide robust reference for developing analytical methods for synthetic biomolecules.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors declare that the content related to the generation of aptamer probes has been authorized by China Patent No. ZL202210658986.6. Apart from this, there are no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)