Localized surface plasmon resonance (LSPR)-based sensing has found wide applications in medical diagnosis, food safety regulation and environmental monitoring. Compared with commercial propagating surface plasmon resonance (PSPR)-based sensors, LSPR ones are simple, cost-effective and suitable for measuring local refractive index changes. However, the figure of merit (FOM) values of LSPR sensors are generally 1-2 orders of magnitude smaller than those of PSPR ones, preventing the widespread use of LSPR sensors. Here we describe an array of submicrometer gold mushrooms with a FOM reaching B108, which is comparable to the theoretically predicted upper limit for standard PSPR sensors. Such a high FOM arises from the interference between Wood's anomaly and the LSPRs. We further demonstrate the array as a biosensor for detecting cytochrome c and alpha-fetoprotein, with their detection limits down to 200 pM and 15 ng ml À 1 , respectively, suggesting that the array is a promising candidate for label-free biomedical sensing.

Reaching the quantum optics limit of strong light-matter interactions between a single exciton and a plasmon mode is highly desirable, because it opens up possibilities to explore room-temperature quantum devices operating at the single-photon level. However, two challenges severely hinder the realization of this limit: the integration of single-exciton emitters with plasmonic nanostructures and making the coupling strength at the single-exciton level overcome the large damping of the plasmon mode. Here, we demonstrate that these two hindrances can be overcome by attaching individual J aggregates to single cuboid Au@Ag nanorods. In such hybrid nanosystems, both the ultrasmall mode volume of ∼71  nm^{3} and the ultrashort interaction distance of less than 0.9 nm make the coupling coefficient between a single J-aggregate exciton and the cuboid nanorod as high as ∼41.6  meV, enabling strong light-matter interactions to be achieved at the quantum optics limit in single open plasmonic nanocavities.

Millimeter-scale 3D superlattice arrays composed of dense, regular, and vertically aligned gold nanorods are fabricated by evaporative self-assembly. The regular organization of the gold nanorods into a macroscopic superlattice enables the production of a plasmonic substrate with excellent sensitivity and reproducibility, as well as reliability in surface-enhanced Raman scattering. The work bridges the gap between nanoscale materials and macroscopic applications.

wileyonlinelibrary.com2D materials. [8][9][10][11][12][13][14][15] As a family member of 2D materials, MoS 2 becomes an attractive hot electron acceptor due to its sizable bandgaps around 1-2 eV and internal photogain with various traps at the interfaces. [16][17][18][19][20] The light harvesting is crucial to achieve high quantum effi ciency of devices. A high plasmon to hot electron conversion effi ciency ≈35% was reported when the scanning probe technique was combined to the detection. [ 21 ] Metal nanostructures are generally regarded as ideal light acceptors, owning to the excitation of surface plasmons (SPs) which can confi ne and manipulate light at the nanoscale, and further applied for the photodetection based on the plasmonic hot electrons. [22][23][24][25][26] After SPs are excited, the energy decays by either radiatively into photons or nonradiatively into hot electrons. Besides the quantum yield, the response rate of photodetector is another vital character for devices, which depends on drift time, diffusion time, and RC time constant. Considering the atomic thickness of MoS 2 , the response rate of an MoS 2 -based photodetector is mainly depended on the drift time of photocarriers in the interface, which indicates that the dynamics of charge transfer between metal and MoS 2 plays an important role in the applications of metal-semiconductor heterojunction.Moreover, the investigation of charge transfer dynamics in the metal-semiconductor interface can be utilized to improve the performance of optoelectronic devices, while the direct experimental observation of ultrafast charge transfer in photoexcited metal nanostructures/MoS 2 heterostructures has not been reported. In addition, due to the limitation of synthesis of large-area MoS 2 , fabricating metal nanostructures on or under the surface of MoS 2 is generally completed by physical preparation techniques, such as electron beam lithography, focused ion beam lithography, and photolithography etc., which are all highcost and complicated. Template electrochemical method used for producing metal nanostructures is a low-cost, high productivity, and large-area fabrication technique. [27][28][29] Therefore, we proposed a template-based sputtering method to fabricate various metallic nanostructures such as nanorod arrays. [ 30 ] An MoS 2 photodetector based on metal nanostructures prepared by this means is supposed to be more attractive compared with other physical preparation methods.2D transition metal dichalcogenides are becoming attractive materials for novel photoelectric and photovoltaic applications due to their excellent optoelectric properties and accessible optical bandgap in the near-infrared to visible range. Devices utilizing 2D materials integrated with metal nanostructures have recently emerged as effi cient schemes for hot electron-based photodetection. Metal-semiconductor heterostructures with low cost, simple procedure, and fast response time are crucial for the practical applications of optoelectric devices. In this paper, template-based ...

Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates controllable chromotropic capability, that is, the ability of reversible colour transformations. This chromotropic capability affords enormous potentials in building functionalized prints for anticounterfeiting, special label, and high-density data encryption storage. With such excellent performances in functional colour applications, this colour-printing approach could pave the way for plasmonic colour printing in real-world commercial utilization.