Construction of Bio-Nano Interfaces on Nanozymes for Bioanalysis

Abstract

Nanomaterials with enzyme-like activity (nanozymes) have been of great interest in broad applications ranging from biosensing to biomedical applications. Despite that much effort has been devoted to the development of the synthesis and applications of nanozymes, it is essential to understand the interactions between nanozymes and most commonly used biomolecules, i.e., avidin, streptavidin (SA), bovine serum albumin (BSA), immunoglobulin G (IgG), and glutathione (GSH), yet they have been rarely explored. Here, a series of bio-nano interfaces were constructed through direct immobilization of proteins on a variety of iron oxide and carbon-based nanozymes with different dimensions, including Fe3O4 nanoparticles (NPs, 0D), Fe3O4@C NPs (0D), Fe3O4@C nanowires (NWs, 1D), and graphene oxide nanosheets (GO NSs, 2D). Such interfaces enabled the modulation of the catalytic activities of the nanozymes with varying degrees, which allowed a good identification of multiplex proteins with high accuracy. Given the maximum inhibition on Fe3O4@C NP by BSA, we established molecular switches based on aptamer and toehold DNA, as well as Boolean logic gates (AND and NOR) in response to both DNA and proteins. Also importantly, we developed an on-particle reaction strategy for colorimetric detection of GSH with ultrahigh sensitivity and good specificity. The proposed sensor achieved a broad dynamic range spanning 7 orders of magnitude with a detection limit down to 200 pg mL–1, which was better than that of an in-solution reaction-based biosensor by 2 orders of magnitude. Furthermore, we explored the mechanisms of the interactions at bio-nano interfaces by studying the interfacial factors, including surface coverage, salt concentration, and the curvature of the nanozyme. This study offered new opportunities in the elaborate design and better utilization of nanozymes for bioanalysis in clinical diagnosis and in vivo detection.

Modulating the Biomimetic and Fluorescence Quenching Activities of Metal–Organic Framework/Platinum Nanoparticle Composites and Their Applications in Molecular Biosensing

“…Surface functionalization of nanomaterials is of great importance in many fields, such as bioanalysis, − bioimaging, , and catalysis. − MOFs are composed of different metal central ions or metal clusters, which can coordinate with many chemical groups. Biomolecules (e.g., DNA and ATP) and inorganic molecules (e.g., H 2 O 2 and phosphates) contain bases, phosphate groups, and hydroxyl groups and, thus, can provide plenty of chemical groups to coordinate with MOFs by formation of chemical bonds.…”

Nanozyme-Based Lateral Flow Immunoassay (LFIA) for Extracellular Vesicle Detection

“…Considering these strengths, Fe 3 O 4 nanozymes have shown potential in a wide range of applications, as reviewed in [ 18 , 19 , 20 ]. Specifically, by merging distinctive physicochemical features and catalytic properties, numerous nanozyme-based platform technologies have been established, for bioanalysis [ 21 ], disease diagnosis [ 22 , 23 ], and therapy [ 24 , 25 ]. Noteworthy among these technologies are nanozyme-based biosensors.…”

A Label-Free Colorimetric Assay Based on Gold Nanoparticles for the Detection of H2O2 and Glucose

“…In recent years, nanomaterials have gained much attention in colorimetric biosensing and diagnostics on account of their unique physical or chemical properties [10][11][12][13][14][15][16][17]. Some nanomaterials such as graphene quantum dots (GQDs)/AgNPs hybrids and Pt nanoclusters [5,18] have been synthesized for the colorimetric detection of H 2 O 2 , but they generally require complex synthesis procedures or time-consuming operations.…”