2D Graphene Oxide/Fe-MOF Nanozyme Nest with Superior Peroxidase-Like Activity and Its Application for Detection of Woodsmoke Exposure Biomarker

Abstract

Emerging nanomaterials such as nanozymes have recently been applied for the immunoassay-based detection of biomarkers. However, the inferior catalytic activity and low water solubility of nanozymes remain as the major limitations compared to natural enzymes. To overcome these limitations, we successfully synthesized a superior nanozyme with a structure of enriched 2D catalytic interface, namely Nanozyme Nest, which was composed of Fe-based metal–organic frameworks (Fe-MOF) and graphene oxide (GO). Then, we applied it in an ultrasensitive enzyme-linked immunosorbent assay (ELISA) for the detection of benzo­[a]­pyrene-7,8-diol 9,10-epoxide–DNA adduct (BPDE–DNA), which is a metabolite of benzo­[a]­pyrene (BP) and used as a typical biomarker of woodsmoke exposure in human blood. The Nanozyme Nest features amplified peroxidase-like catalytic ability from graphene and Fe-MOF due to their large surface area and abundant active sites. By using the proposed Nanozyme Nest-based ultrasensitive ELISA, the BPDE–DNA could be detected at a level as low as 0.268 ng/mL, and the obtained sensitivity was much higher than most of the widely used methods. Our work provides a novel strategy to design ultrasensitive immunosensors with advantages of amplified catalytic activity and improved water solubility compared to classic nanozymes. This illustrates the promising applications of the Nanozyme Nest-based immunosensors in point-of-care settings to conveniently detect exposures and diagnose diseases.

Nanozyme-based electrochemical biosensors for disease biomarker detection

“…42 For instance, Ruan et al reported the third generation of 2D GO/Fe-MOF hybrid nanozymes, named nanozyme nest, which was used in a conventional sandwich ELISA to detect benzo[a]pyrene-7,8-diol 9,10-epoxide−DNA adduct (BPDE−DNA), a woodsmoke biomarker found in the blood. 133 This method showed enhanced sensitivity for the oxidation of TMB by dual peroxidase active nanozyme nest(Fe-MOF and GO).…”

“…Electrostatic interactions between GO and Fe-MOF hold them together. 133 A similar phenomenon was used for the synthesis of GO-AuNP nanozymes. During the aging step of the synthesis, gold ion was adsorbed on the surface of the GO.…”

Liposome‐Boosted Peroxidase‐Mimicking Nanozymes Breaking the pH Limit

“…Nanozymes have recently shown great potentials in biomedical, [1–4] analytical, [5, 6] and environmental applications [7, 8] . Compared to their protein counterpart, nanozymes possess several unique advantages such as tolerance to harsh environment, resistance to protease digestion, and low cost [1, 9–11] .…”

“…[4,[19][20][21] While most peroxidase nanozymes work optimally at pH 4, their activity at neutralp Hi sn early fully inhibited. [9,22] Various methods were devoted to improve the catalytic activity of peroxidasenanozymes towards neutral pH, such as surfacemodification with metal ions, [6,13] polymers, [23] amino acids, [24] and small molecules. [25,26] For instance,a denosine triphosphate (ATP)-modifiedF e 3 O 4 nanoparticles showede nhanced activity at physiological pH.…”

Regulation of the Peroxidase‐Like Activity of nGO, MoS2 and WS2 Nanozymes by Using Metal Cations

“…On the other hand, the peroxidase‐like activity of WS 2 has been used for colorimetric glutathione detection [13] . The enzymatic property of nGO has been evaluated for pesticide [14] and woodsmoke exposure biomarker [15] detection. Though their applications are highly appealing, the environmental factors diminishing or boosting the reaction rate have to be taken in account for the development of robust applied systems.…”