ZIF-8 Metal–Organic Framework Electrochemical Biosensor for the Detection of Protein–Protein Interaction

Abstract

In this study, a novel label-free electrochemical biosensor based on the zeolitic imidazole framework (ZIF-8) was developed for monitoring protein–protein interactions (PPIs). ZIF-8 was deposited on interdigitated electrodes and employed as a transducing material and simultaneously carried the thioredoxin-1 (Trx-1) protein, followed by the deposition of increased concentrations of the cytoplasmic domain of a disintegrin and metalloproteinase 17 (ADAM17cyto) known as the Trx-1 binding partner. Structural and morphological characterizations were used to validate and verify the formation of ZIF-8. The ZIF-8 crystals showed a rhombic dodecahedral structure with mainly exposed (011) facets, a mean particle size of 205 (±22) nm, and a ZIF-8 film thickness around 61 (±6) nm. The interaction between Trx-1 and ADAM17cyto proteins was analyzed through electrochemical impedance spectroscopy (EIS). The results indicate a linear and inverse relationship between the impedance responses at 0.1 Hz for ADAM17cyto concentrations from 50 nM to 8 μM, with a coefficient of variation from 1.0% to 11.4%. The proposed biosensor also displayed a significant selectivity and stability verified by using ADAM17cyto mutant and BSA as controls. As a proof-of-concept, we compared the results with a widely used type of PPI assay based on antibody recognition, the solid-phase binding assay, using the same proteins. The solid-phase binding assay was able to detect a significant binding only in ADAM17cyto concentrations above 0.5 μM, with a coefficient of variation varying from 5.4% to 27.5%. The results demonstrate that the developed biosensor was 10× more sensitive and reproducible than the conventional solid-phase binding assay. Furthermore, the developed electrochemical biosensor based on ZIF-8 provides a faster, label-free, and low-cost detection analysis, representing a novel strategy in detecting PPIs.

Metal−Organic Frameworks: Why Make Them Small?

“…[ 61 ] Bufon, Leme, and co‐workers recently used a similar approach to grow ZIF‐8 on electrodes, which they used as transducers to monitor protein−protein interactions involving ADAM17cyto (Figure 3e). [ 62 ] Alternatively, Zhang, Wang, and co‐workers used a seeding‐growth approach to create artificial MOF‐based channels analogous to biological ion channels, which showed remarkable ion selectivity, permeability, and rectification properties. [ 63 ] Specifically, they grew UiO‐66‐(COOH) 2 particles (≈43.7 nm) as embedded seeds in bullet‐shaped subnanochannels to construct asymmetrically structured crystalline MOF subnanochannels.…”

Hierarchical Design of Functional, Fibrous, and Microporous Polymer Monoliths for the Molecular Recognition of Diethylstilbestrol

“…ZIF-8 nanocrystals exhibit intrinsically high porosity and thermal stability and provide redox-active sites or catalytic supports, which enable practical applications such as separation, delivery, or catalysis . Furthermore, the inorganic materials contain imidazole units that play a catalytic role as a Lewis basic site for many organic reactions, for example, transesterification, cycloaddition, nucleophilic ring-opening, and condensation reactions. ,− Herein, we were able to newly demonstrate the catalytic activity of 5 in the thiol–epoxy “click” polymerization of the diglycidyl monomer ( 7 ) and dithiol monomer ( 8 ), as shown in Figure a. Even a small amount of 5 (1 wt %) could efficiently polymerize a 1:1 mixture of both difunctional monomers in THF at 60 °C, which formed the linear polymer chains of 9 via the addition polymerization reaction.…”

Reticular Nanoscience: Bottom-Up Assembly Nanotechnology

“…Simultaneously, the high control over their miniaturization goes hand in hand with their facile integration onto surfaces and into devices, favoring the production of sensors that are more accessible, easier to use, and cheaper to prepare. This was impressively exemplified with the preparation of sensors based on ZIF-8­(Zn) nanoparticles for the detection of either the carbon dioxide (CO 2 ) levels or protein–protein interactions …”