A Hybrid of FeS₂ Nanoparticles Encapsulated by Two-Dimensional Carbon Sheets as Excellent Nanozymes for Colorimetric Glucose Detection

Abstract

Recently, the development of nanozymes with high catalytic performance is gaining more and more attention due to the ever-growing demands for their practical applications. The elaborate design of its morphology has demonstrated to be an effective approach to improve the performance of these nanozymes. Herein, a hybrid of iron disulfide nanoparticles (FeS2 NPs) encapsulated by two-dimensional (2D) carbon nanosheets (NSs), denoted as FeS2@C NSs, demonstrates both superior peroxidase-like activity and excellent stability. The incorporation of 2D carbon sheets endows the proposed FeS2@C nanozymes with high specific surface area, providing abundant active sites to facilitate the contact with substrates. Moreover, the embedded FeS2 NPs are kept from aggregation due to the encapsulation and confinement of 2D carbon sheets, avoiding the conventional failure of single-component nanozymes. Based on glucose oxidase (GOx) and the elaborately designed FeS2@C nanozymes, a colorimetric method for glucose detection is then developed with excellent simplicity and sensitivity. The detection limit of the sensing platform is as low as 0.19 μM for a glucose assay. More notably, this method can be successfully employed for the glucose assay in some real samples, indicating the great potential of this FeS2@C NS-based nanozymes in the fields of biotechnology and clinical diagnostics.

Enzyme Mimics for Engineered Biomimetic Cascade Nanoreactors: Mechanism, Applications, and Prospects

“…[ 89 ] Encouraged by GOx‐POD cascade catalysis, numerous biomimetic GOx‐POD cascade nanoreactors have been constructed using POD‐mimicking nanozymes to replace natural HRP in traditional GOx‐POD cascade catalysis. [ 23b,34,36,37,43–47,90 ] POD‐mimicking nanozymes like WO x quantum dots (QDs), [ 42 ] cobalt‐based polyoxometalates, [ 38 ] Au‐Ni doped graphitic carbon nitride sheets (Au‐Ni/g‐C 3 N 4 ), [ 39 ] Au–Ag hollow nanotriangles, [ 41 ] single iron site nanozymes, [ 23a ] FeS 2 @carbon nanosheets, [ 40 ] and MOF‐based nanozymes (e.g., MIL‐53(Fe), Cu‐MOF, PtNPs/Cu‐TCPP(Fe), MOF‐808, and Co‐Ferrocene MOF) [ 16b,54–56,58 ] have been used for the development of biomimetic GOx‐POD cascade catalytic nanoreactors. For instance, Peng et al.…”

“…[ 42 ] Similarly, the POD‐mimicking cobalt‐based polyoxometalate nanozyme (i.e., CoPW 11 O 39 ), Au‐Ni/g‐C 3 N 4 , and FeS 2 @carbon nanosheets were combined with GOx to construct a GOx‐POD cascade system. [ 38–40 ] Interestingly, Chen et al. integrated a single iron site nanozyme and GOx into an agarose‐based hydrogel to develop a multienzyme biocatalytic cascade platform for glucose detection.…”

“…[ 17a,21a,91,123 ] Due to the excellent cascade catalytic performance of the substrate transformation and remarkable signal amplification, nanozyme‐engineered biomimetic cascade nanoreactors exhibit great potential for colorimetric biosensing applications. [ 4a,23b,40,43,44,53,60,68,107–109,124 ] For example glucose levels are an indicator reflecting human health, and therefore the monitoring of glucose levels is extremely important for medical diagnosis. To date, a great number of nanozyme‐engineered biomimetic cascade nanoreactors have been used for colorimetric glucose sensing.…”

High-Performance Self-Cascade Pyrite Nanozymes for Apoptosis–Ferroptosis Synergistic Tumor Therapy

“…Recently, the peroxidase-like activity of FeS 2 nanomaterials was investigated, and their enzymatic activities have been used for the sensitive detection of H 2 O 2 or glutathione. , Hybrids comprising FeS 2 and other nanomaterials were also constructed. Enhanced peroxidase activity and better performance in the application of biosensors than FeS 2 nanozyme were exhibited. , However, there is no report on exploring the enzymatic activity of FeS 2 nanomaterials for in vivo application especially for tumor therapy.…”

“…Enhanced peroxidase activity and better performance in the application of biosensors than FeS 2 nanozyme were exhibited. 31,32 However, there is no report on exploring the enzymatic activity of FeS 2 nanomaterials for in vivo application especially for tumor therapy.…”