Plasmonic Superlattice Membranes Based on Bimetallic Nano-Sea Urchins as High-Performance Label-Free Surface-Enhanced Raman Spectroscopy Platforms

Abstract

On the basis of an abundance of elemental plasmonic nanocrystals identifiable by their unique morphology and intrinsic optoelectronic properties, it is necessary to rationally tailor the structural parameters to optimize the functionalities of nanoassemblies for application as plasmonic circuits/devices. Among them, the plasmonic superlattice membrane has emerged as a novel optically active metamaterial, which is constructed by nanocrystals at a twodimensional (2D) plane with a highly ordered structure and strong plasmonic coupling interactions. Here, we report on the fabrication of a novel plasmonic superlattice membrane using bimetallic core−shell nano-sea urchins (Nano-SEUs) as meta-atoms. Under the guidance of soft-ligand balancing in conjugation with drying-mediated self-assembly at the air/water interface, well-defined giant 2D superlattices with total lateral dimensions of up to 5 mm wide and 80 nm thick have been synthesized, corresponding to an aspect ratio of 62 500. Programmable morphology control over the Nano-SEUs has been achieved in high yield by rationally tuning the spiky branches as well as the thickness of the silver shell, allowing systematic variation of the plasmonic properties of the membrane. Such superlattice membranes exhibited a strong and reproducible surface-enhanced Raman spectroscopy (SERS) signal that originates from interparticle coupling and electric (E)-field enhancement, enabling an enhancement factor of up to 10 6 . We also demonstrated that the fabricated membrane allows the label-free SERS detection of dopamine from 0.1 nM to 1 μM. Thus, this giant Nano-SEU assembled superlattice membrane can be used as a SERS substrate for on-spot biomarker detection, which paves a robust and inexpensive avenue for highly sensitive and reliable biomedical sensing and diagnostics.

Vein-Like Ni-BTC@Ni3S4 with Sulfur Vacancy and Ni3+ Fabricated In Situ Etching Vulcanization Strategy for an Electrochemical Sensor of Dopamine

“…In recent years, detection technologies have played an important role in clinical diagnostics, disease treatment, and anticancer drug development. , At present, the detection and analysis methods for DA mainly include high-performance liquid chromatography (HPLC), chemiluminescence, spectrophotometry, colorimetry, surface-enhanced Raman spectroscopy (SERS), and electrochemical methods . Among the above technologies, electrochemical sensing technology has attracted much attention because of its simple operation, high sensitivity, fast detection, low cost, and other advantages and has been widely applied in the detection of food, biological molecules, environment polutants, , and so on.…”

Three-Dimensional Au Octahedral Nanoheptamers: Single-Particle and Bulk Near-Field Focusing for Surface-Enhanced Raman Scattering

“…The development of structurally complex plasmonic nanoparticles (NPs) has gained a great deal of interest due to the unique optical properties that result from the NPs’ localized surface plasmon resonance (LSPR), a collective oscillation of free conduction electrons under excitation by resonant light waves. Since the LSPR is highly sensitive to the size, shape, and surrounding environment of the NPs, , a wide variety of plasmonic NPs has been designed, including Au nanostars, bipyramids, chiral NPs, and nanoframes (NFs). − In addition to altering the morphology of individual NPs, constructing spatial assemblies using Au nanospheres (Au NSs) as building blocks is another effective strategy for endowing unique optical properties to NP systems. The arrangement-dependent optical properties of these assemblies differ from those of their single-particle counterparts. , Representative examples of such assemblies include one-dimensional (1D) chain-like structures, , two-dimensional (2D) trimer structures, and three-dimensional (3D) hexamer structures.…”

Advances in surface‐enhanced Raman spectroscopy technology for detection of foodborne pathogens

“…Hence, achieve the capture of pathogenic bacteria and the sensitization of the Raman signal. Nanosol substrates are simple, inexpensive, and shape‐controlled and are one of the earliest and most popular substrate materials used in SERS detection (Feng et al., 2022; Mitra & Basak, 2022; Zhang, Wang, et al., 2022).…”