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Recently, 2D magnetic materials have attracted much attention due to their potential applications in spintronic devices. Chromium telluride (CrTe) flakes have been reported for hard magnetism with a strong perpendicular anisotropy. However, the synthesis of large‐scale CrTe nanoflakes on SiO2/Si substrate is still a challenge. Here, we report the synthesis of large‐scale CrTe nanoflakes with a size of up to ∼250 μm on a SiO2/Si substrate via chemical vapor deposition (CVD). Our work demonstrated an effective pathway to synthesize large‐scale 2D transition metal tellurides. [ABSTRACT FROM AUTHOR]

Platinum diselenide (PtSe2), an emerging two-dimensional transition metal dichalcogenide, exhibits thickness-dependent refractive index, and hence, intriguing optical properties. Here, we employ it as a plasmonic sensing substrate to achieve significant enhancement in Goos-Hänchen shift sensitivity. Through systematic optimization of all parameters, four optimum sensing configurations have been achieved at different wavelengths ranging from visible to near-infrared region, where the Goos-Hänchen shift sensitivity receives four times enhancement in comparison with the conventional bare gold sensing substrate. There is a linear range of Goos-Hänchen shift with the tiny change of refractive index for each optimal configuration. The detection limit of the refractive index change can be as low as 5 × 10−7 RIU which is estimated to be lower by 2 orders of magnitude, and the corresponding sensitivity of biomolecules has a 1000-fold increment compared with that of bare gold-based sensors. [ABSTRACT FROM AUTHOR]

Layered transition metal dichalcogenides (TMDCs) within two dimension (2D) have been gaining widespread consideration due to their exclusive optoelectronic properties. Here, we propose a hybrid nanostructured plasmonic biosensor composed of layered materials (TMDCs and graphene) on a Au film intended for increasing the Goos–Hänchen (GH) shift of the reflected light. MoS2 and WS2 are chosen as the TMDCs to constitute the sensing materials. We provide a detailed simulation and theoretical analysis of the performance of the sensor based on surface plasmon resonance (SPR) composed of the proposed hybrid nanostructure for wavelengths spanning from the visible to near-IR spectral region. The sensing performance is evaluated in terms of sensitivity, figure of merit (FoM), and enhancement factor. Four optimal configurations are achieved at different excitation wavelengths, where the largest enhancement factor of sensitivity is over five times in comparison to conventional bare gold sensors. Also, the detection limit of the refractive index (RI) change is decreased by two orders of magnitude and its corresponding sensitivity shows over ten times improvement. [ABSTRACT FROM AUTHOR]

Plasmonic sensing relies on the interaction between the electromagnetic light wave and free electrons that reside at the interface of two materials, one of them being a metal. Surface plasmon resonance (SPR)‐based biosensing has distinct advantages of providing real‐time and label‐free detection technique that is capable of giving accurate and repeatable results. 2D nanomaterials (graphene and transition metal dichalcogenides [TMDCs] such as MoS2 and WS2) have recently gained high popularity in the field of biomedical sciences. Using Biacore commercial SPR machine manufactured by GE Healthcare, the efficacy of various combinations of these materials coated on the plasmonic metal gold (Au) (Au + MoS2, Au + WS2, Au + graphene, Au + graphene + MoS2, and Au + graphene + WS2) is evaluated, in enhancing the sensitivity of the biosensor as compared with the standard Kretschmann configuration (only Au). Some simulation results are also presented at incident light wavelengths of 633 and 785 nm that are based on the angular interrogation method. To conclude, it is found that the sensitivity in the increasing order is: only Au < Au + MoS2 < Au + WS2 ≈ Au + graphene < Au + graphene + MoS2 < Au + graphene + WS2. [ABSTRACT FROM AUTHOR]