Highly efficient colorimetric detection of target cancer cells utilizing superior catalytic activity of graphene oxide–magnetic-platinum nanohybrids

Abstract

Enzyme-linked immunosorbent assays (ELISAs) have most widely been applied in immunoassays for several decades. However, several unavoidable limitations (e.g., instability caused by structural unfolding) of natural enzymes have hindered their widespread applications. Here, we describe a new nanohybrid consisting of Fe₃O₄ magnetic nanoparticles (MNPs) and platinum nanoparticles (Pt NPs), simultaneously immobilized on the surface of graphene oxide (GO). By synergistically integrating highly catalytically active Pt NPs and MNPs on GO whose frameworks possess high substrate affinity, the nanohybrid is able to achieve up to a 30-fold higher maximal reaction velocity (V(max)) compared to that of free GO for the colorimetric reaction of the peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB), and enable rapid detection of target cancer cells. Specifically, using this new assay system, clinically important breast cancer cells are detected in a 5 min time period at room temperature with high specificity and sensitivity. The remarkably high capability to catalyze oxidation reactions could allow the nanohybrid to replace conventional peroxidase-based immunoassay systems as part of new, rapid, robust and convenient assay systems which can be widely utilized for the identification of important target molecules.

Carbon Nanozymes: Enzymatic Properties, Catalytic Mechanism, and Applications

“…[116,117,127,134,155] Song et al first reported af olic acidconjugated graphene-hemin hybrid (GFH) for selective, quantitative,a nd fast colorimetric detection of cancer cells by using its peroxidase-like activity (Figure 7a). [116,117,127,134,155] Song et al first reported af olic acidconjugated graphene-hemin hybrid (GFH) for selective, quantitative,a nd fast colorimetric detection of cancer cells by using its peroxidase-like activity (Figure 7a).…”

“…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]…”

“…[116,117,127,134,139,155] As folate receptors are Figure 5. [116,117,127,134,139,155] As folate receptors are Figure 5.…”

Fe3O4 nanoparticles on graphene oxide sheets for isolation and ultrasensitive amperometric detection of cancer biomarker proteins

“…Fe 3 O 4 nanoparticles were synthesized by a solvo-thermal method (Deng et al, 2005) (see SI), Graphene Oxide (GO) was prepared using a modified Hummer’s method (SI) (Kim et al, 2014; Hummers and Offeman, 1958). Briefly, 50 mg of Fe 3 O 4 nanoparticles were sonicated 5 min with 10 mL 0.1 mg/mL poly(diallydimethylammonium chloride) (PDDA) in water, magnetically separated, washed 3x with water, and re-suspended in 25 mL water.…”

Mesoporous carbon-enriched palladium nanostructures with redox activity for enzyme-free electrochemical immunoassay of brevetoxin B

“…Recent research has looked to explore innovative and powerful functionalized nanostructures by controlling and tailoring their properties in a very predictable manner to meet the requirement of specific applications [13][14][15]. Kim et al designed a highly efficient enzyme-free colorimetric detection of target cancer cells utilizing superior catalytic activity of graphene oxide-magnetic-platinum nanohybrids [16]. Vabbina et al.…”