Magnetic RuCo aerogels with enhanced peroxidase-like activity by regulation of boron and oxygen vacancies for colorimetric biosensing applications.

ABSTRACT

Metallic aerogels (MAs) are self-supported porous nanomaterials with excellent catalytic activity, which could be a promising candidate for high-performance nanozymes. The interface regulation by heteroatom and vacancies is an effective strategy for boosting the enzyme-mimicking activity. Herein, magnetic RuCo aerogels with doping of boron and oxygen vacancies were prepared by a one-pot spontaneous NaBH4 gelation method under a low temperature. The three-dimensional network structure with high specific surface area and interlinked pores of RuCo aerogels afford abundant active sites to facilitate the interaction with substrates. Moreover, the monolithic structure avoided conventional aggregation, thus enhancing stability during catalysis. Introducing elemtal boron and oxygen vacancies adjusted the electronic structure of RuCo aerogels to achieve enhanced enzyme-like performances. It is found that the RuCo aerogel nanozyme can mimic nature peroxidase, demonstrating their viable applications in the bioassay of H2O2 and glucose. The constructed glucose sensor possesses acceptable sensitivity and stability with a linear range of 0.002 ~ 5 mM and a low detection limit (1.66 µM). This work provides insights into the rational design of advanced nanozymes and paves the avenue for the applications of metallic aerogels in the bioassay field. A boron-doped RuCo bimetallic aerogel with rich oxygen vacancies was prepared by a facile self-assembly method under an ice bath. The unique physical and electronic structure of RuCo aerogel results in the improvement of the intrinsic peroxidaselike activity, and thus, a sensitive and robust colorimetric glucose sensor could be developed.