In Situ Synthesis of Self-Assembled Three-Dimensional Graphene–Magnetic Palladium Nanohybrids with Dual-Enzyme Activity through One-Pot Strategy and Its Application in Glucose Probe

Abstract

The self-assembled three-dimensional graphene nanohybrids with in situ-formed Fe3O4 and Pd nanoparticles on it (3DRGO_Fe3O4-Pd) are first synthesized by the one-pot solvothermal method, which have intrinsic peroxidase-like and oxidase-like activity. The catalytic mechanism is analyzed by the electron spin resonance (ESR), fluorescence, and electrochemical methods. The mimic enzyme catalytic activity of 3DRGO_Fe3O4-Pd is much higher than those of monometallic loaded nanohybrids and their physical mixture, probably caused by synergistic effect between Pd and Fe3O4 nanoparticles. The 3DRGO_Fe3O4-Pd nanohybrids was reproducible, stable, and reusable. After 10 cycles, the catalytic activity was still higher than 90%, and the morphology and structure were basically unchanged. Based on its high peroxidase-like activity, especially the enhanced affinity toward H2O2, a new colorimetric detection method for reduced glutathione (GSH) and glucose has been designed using H2O2 as an intermediary, which provides a simple, sensitive, and selective way to detect urine glucose of diabetes with a wide linear range and low detection limit.

Carbon Nanozymes: Enzymatic Properties, Catalytic Mechanism, and Applications

“…Besides their intrinsic enzymatic activity,CNMs and their derivatives can be also utilized as modulators to further improve the catalytic activity and stability of artificial peroxidase.M any classic artificial peroxidases,f or instance, metal oxides (for example,F e 3 O 4 , FeO x H, [94] Fe 2 O 3 , [95][96][97] Co 3 O 4 , [98][99][100] ZnO, [101] CuO, [102][103][104][105] Cu 2 O, [106] CeO 2 , [92] Co-Fe 2 O 4 , [107,108] and WO 3 [109] ), metal hydroxide, [110] metal chalcogenides (for example,C oSe 2 , [111] CuS, [112,113] and MoS 2 [114] ), metal nanoparticles (for example,P t, [92,[115][116][117][118][119][120][121] Pd, [82,88,122,123] Au, [84,88,[124][125][126][127][128][129][130][131][132][133]…”

A highly conductive porous graphene electrode prepared via in situ reduction of graphene oxide using Cu nanoparticles for the fabrication of high performance supercapacitors

“…20 Although some nanocrystals decorated on GO or RGO were fabricated successfully through various reduction route without any extra reductants and capping agents, the routes are still based on in situ hybridization. [21][22][23][24][25][26] According to recent findings, GO can be directly reduced by active metals, such as Al, Fe and Cu. [27][28][29][30][31][32][33] For example Qu et al 28 used this method to deposit RGO on the arbitrary conductive target supported by active metal in order to construct 3D RGO network.…”

Highly sensitive on-site detection of glucose in human urine with naked eye based on enzymatic-like reaction mediated etching of gold nanorods

“…2D). The detection limit was calculated to be 0.1 μM (3σ rule), which is two orders of magnitude lower than other GNRs-based glucose sensors (Liu et al, 2013;Saa et al, 2014) and is almost the lowest among nanoparticle-based glucose sensors (Table S1, Supplementary Information) (Bi et al, 2015;Bo et al, 2013;Jiang et al, 2010;Kong et al, 2014;Luo et al, 2015;Radhakumary and Sreenivasan, 2011;Shen and Xia, 2014;Shiang et al, 2009;Su et al, 2012Su et al, , 2015bXia et al, 2013;Yi et al, 2013;Zayats et al, 2005;Zhao et al, 2015;Zheng et al, 2015). In addition, the small error bar of the data indicates the method has very high stability (Fig.…”

“…The development of colorimetric assay for urine glucose detection has attracted much attention because of its low cost, visuality and potential for on-site/ in-home application. Even though many colorimetric glucose sensors have achieved satisfactory sensitivity, yet the real practicability is still limited by the need of complex sample pretreatment, such as centrifugal separation (Bo et al, 2013;Su et al, 2012Su et al, , 2015aZheng et al, 2015).…”