Multibranched Au–Ag–Pt Nanoparticle as a Nanozyme for the Colorimetric Assay of Hydrogen Peroxide and Glucose

Abstract

Many studies have recently produced artificial enzymes with metal nanoparticles (NPs) to overcome the limitations of natural enzymes, such as low stability, high cost, and storage problems. In particular, gold NPs exhibit peroxidase-like activity and are strongly influenced by external parameters, such as pH, temperature, size, shape, and functional layer, which change the enzyme activity. Here, chitosan-capped multibranched Au−Ag−Pt NPs (CCNPs) that mimic peroxidase were synthesized using various peroxidase-mimicking strategies. The results demonstrated that enzyme activity sequentially increased because of the multibranched Au−Ag NPs coated with Pt and chitosan. The enzyme activity of the particle was evaluated through the oxidation of 3,3′,5,5′tetramethylbenzidine (TMB), which causes a color change into blue. This change was observable with the naked eye and could be used practically. The color change depended on the concentration of hydrogen peroxide (H 2 O 2 ), and it was shown that the CCNPs could be applied to measure H 2 O 2 with a limit of detection (LOD) of 0.054 mM. Furthermore, with glucose oxidase, the CCNPs can be used for glucose detection with an LOD of 0.289 mM. Also, the potential of the CCNP application in human serum was shown through the serum test. Thus, this study suggested the utilization of the multibranched Au−Ag−Pt NPs that mimic the peroxidase activity of natural enzymes and the possibility of application in various biological analyses.

Serine-Modified Au@Cu2O Core–Shell Nanoparticles for Catalysis-Mediated Colorimetric Detection of Small Molecules

“…Compared to other peroxidase-like nanomaterials, Au@Cu 2 O-s HNS showed relatively fast maximal velocities of catalytic reaction for H 2 O 2 and TMB, indicating its superior catalytic ability (Table S2). ,− The higher catalytic efficiency by Au@Cu 2 O-s NCs was obtained under the higher concentrations of H 2 O 2 and TMB (Figure S7). Interestingly, exceptionally high Michaelis constants of Au@Cu 2 O-s for H 2 O 2 and TMB were obtained, which might be attributed to the serine barrier-induced inhibition of surface affinity between NCs and substrates.…”

Nanoscale materials at work: Mapping emerging applications in energy, medicine, and beyond

“…Examples of recent patents by KAIST involve gas sensors, 484,485 a cerium oxide-based sensor that can be used to detect hydrogen peroxide 486 and a CNT based sensor for virus detection. 487 Similarly, patents filed by KIST cover a range of sensors including colorimetric sensors based on gold nanoparticles, 488 wearable sensors utilizing silver nanowire and SWCNT 489 and nitrogen dioxide gas sensors using SWCNTs decorated with carbon dots, 490 among many others.…”

Enhanced Peroxidase-Mimic Catalytic Activity via Cerium Doping of Strontium-Based Metal–Organic Frameworks with Design of a Smartphone-Based Sensor for On-Site Salivary Total Antioxidant Capacity Detection in Lung Cancer Patients

“…Also, nanozymes can speed up the oxidation of many chromogenic substrates to produce colorimetric signals. This opens up new ways to improve colorimetric sensors. , Until now, nanomaterials based on noble metals exhibiting peroxidase-like activity for the detection of TCA have garnered considerable interest, such as Bi 0.3 Fe 1.7 MoO 6 , CuBi bimetallic, CoOOH, Mn@Co3O4, Au nanoparticles (NPs), Au–Ag–Pt NPs, Pd–Pt–Ru, and BSA-AuNCs-TH . However, because of the high cost of noble metals, their applicability has been severely limited.…”