2D Van der Waals Heterostructures for Chemical Sensing

Abstract

During the last 15 years, 2D materials have revolutionized the field of materials science. Moreover, because of their highest surface‐to‐volume ratio and properties extremely susceptible to their interaction with the local environment they became powerful active components for the development the high‐performance chemical sensors. By combining different 2D materials to form van der Waals heterostructures (VDWHs) it is possible to overcome the drawback of individual materials (such as inertness and zero‐bandgap of pristine graphene and less environmental stability of transition metal dichalcogenides). Meanwhile, VDWHs possess unprecedented and fascinating properties arising from the intimate interaction between the components, which can yield superior sensitivities, higher selectivity, and stability when employed to detect gases, biomolecules, and other organic/inorganic molecules. Herein, the latest developments and advances in the field of chemical sensors based on VDWH of 2D materials, with specific insight into the sensing mechanisms, are reviewed and future directions, challenges, and opportunities for the development of the next generation of (bio)chemical sensors with potential impact in environmental sciences and biomedical applications, and more specifically in (bio)chemical defense, industrial safety, food, and environmental surveillance, and medical (early) diagnostics, are discussed.

Technology Roadmap for Flexible Sensors

“…The growing healthcare/medical gas sensors area may provide an impetus to continue to develop bioaffinity-based sensing . In comparison, nanomaterials with tunable structures and chemistries capable of dry-phase sensing seem to be more technically and economically viable. ,, Metal–organic frameworks (MOFs) are particularly attractive because their porous structures can selectively adsorb or filter gas molecules (Figure b) . However, a limited understanding of gas–MOF interactions, as well as the structure–property relationships of MOFs prevents generalized design methodologies for MOF-based gas sensors to cover wide ranges of VOCs.…”

“…Various nanomaterials such as conducting polymer nanofibers, graphene, nanostructured gold, MOFs, and transition metal nanoparticles ( e.g. , Fe 3 O 4 and NiO) are often utilized on the working electrode in electrochemical sensors as they can enhance the electrochemically active surface area and electron transfer dynamics, resulting in higher detection signals. , Recent reports show that laser-engraved graphene enabled the detection of sweat uric acid, tyrosine, and cortisol at sub-micromolar levels, , and dendritic gold nanostructures were successfully used to monitor micromolar levels of vitamin C and glucose in sweat. , Besides nanomaterials, micro- to macro-scale approaches can also increase electroactive surface areas, using printable ink formulations and 3D hybrid electrode structures. , …”

“…Flexible sensors have matured tremendously since the beginning of the 21 st century. Starting with pressure sensor arrays on plastic films, flexible sensors now cover a wide range of physical and chemical sensing modalities, including temperature, strain, electrophysiology, ions, biomarkers, metabolites, gases, and many more. − Substrates are not limited to plastic films but can also be ultra-thin plastic foils, porous polymer mats/meshes, paper, , elastomers, and hydrogels . From single sensors to sensor arrays, from stand-alone sensors to integrated sensing systems, the development has been astonishing, and fascinating applications including sweat-based stress monitoring ,, and remote robotic control through skin sensor-enriched virtual reality have been demonstrated.…”

Dielectrics for Two-Dimensional Transition-Metal Dichalcogenide Applications

“…Quantum sensing refers to the measurement of a physical quantity (classical or quantum) using a quantum system or a quantum property of the sensor . Deploying 2D materials in sensing experiments is advantageous when high surface-to-bulk ratio, , close proximity to the sensing targets, or properties of the 2D material are desirable for the application. We can broadly classify quantum sensing experiments with TMDs based on the degrees of freedom leveraged.…”

Controllable Preparation of 2D V2O5 Peroxidase‐Mimetic Nanozyme to Develop Portable Paper‐Based Analytical Device for Intelligent Pesticide Assay

“…Since the breakthrough investigation by Geim and Novoselov, 2D nanosheet, featuring high light-absorbing capacity, increased responder locus, accelerated carrier separation and charge transfer, and ameliorative surface-catalyzed reaction efficiency, has indeed emerged as a novel material for application in many fields, [14][15][16][17][18][19][20] such as electrocatalysis, [21] photocatalysis, [22] biomedical engineering, [23,24] optoelectronic, [25,26] and biological and chemical sensing. [27][28][29][30][31] Moreover, via ingeniously adjusting the morphology and composition, the as-prepared 2D nanosheet may have unimagined "bioenyzme-mimetic" activity, named 2D nanozyme, which shows great applications in catalytic oxidation for target analyte sensing, an emerging pesticideresponse modality.…”