Towards Multi-Analyte Detection with Field-Effect Capacitors Modified with Tobacco Mosaic Virus Bioparticles as Enzyme Nanocarriers

Abstract

Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO2-Ta2O5 layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1–3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta2O5-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.

Facile Purification and Use of Tobamoviral Nanocarriers for Antibody-Mediated Display of a Two-Enzyme System

“…All these options are realized if conversion reactions by, e.g., enzymes immobilized on chip surfaces, are recorded in small or miniaturized devices, via detecting electrochemical changes arising from the generation or consumption of electrons or protons. Respective sensor chips equipped with TMV adapter coatings as enzyme-displaying nanomaterial have proven their beneficial properties repeatedly [ 41 , 42 , 44 , 48 , 49 ]. Hence, we sought to evaluate if TVCV PA immobilization on such chips can follow the protocols established for TMV before.…”

“…Its easy production, physical and chemical stability, and options for generating TMV-derived designer particles of altered shapes offer versatile prospects for multi-functionalization with, e.g., peptides, enzymes, drugs, and/or synthetic and inorganic compounds, and corresponding uses [ 31 ]. Increasing numbers of studies have employed TMV-based adapters for the display of enzymes, and for installing enzymatic and other types of bioreceptors in different types of sensors [ 20 , 25 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. TMV, however, does not tolerate extensive genetic modifications.…”

Advances of Structural Design and Biomedical Applications of Tobacco Mosaic Virus Coat Protein

“…This EISCAP sensor can also be used for multianalyte fixation such as penicillinase and urease. [ 73 ]…”

Soft Sub‐Structured Multi‐Material Biosensor Hydrogels with Enzymes Retained by Plant Viral Scaffolds

“…With the spatially well-defined GM spot array and a known number of docking sites exposed on the TMV nanocarriers, it will be feasible to integrate a defined number of enzyme molecules per spot and to combine distinct enzymes on one biosensor platform via GM formulations with different nanoparticle-enzyme conjugates. TMV has already been successfully applied in various sensor layouts [39][40][41][62][63][64][65][66][67][68][69][70] and was shown to stabilize distinct enzymes including penicillinase in label-free electrochemical field-effect biosensors that retained their perfor-mance for at least a year of repetitive use. [41] This points to the future potential of the combination of plant viral bioscaffolds with hydrogel soft biosensors, for example, as sensor domains in 3D cell cultures grown for tissue replacement, in implanted online sensors, or for in situ detection purposes for process monitoring in biotechnological or food fabrication fermenters.…”