Gap-mode TERS on 4-Nitrothiophenol (4-NTP) monolayers
Tip-enhanced Raman spectroscopy (TERS) provides nanoscale vibrational contrast by combining optimized probe geometries, controlled tip–sample coupling and carefully aligned optical excitation. Through the simultaneous acquisition of AFM topography, near-field VIS-SNOM signals, and Raman spectra, the IR-neaSCOPE+TERs platform enables users to actively monitor the experimental conditions required to achieve reliable TERS enhancement.
In this study, a gold-coated probe confines the electromagnetic field into the nanometer-sized gap between tip and gold surface, generating strong near-field enhancement in the gap-mode regime. Under these optimized circumstances, molecular monolayers such as 4-nitrothiophenol (4-NTP) on Au(111) exhibit distinct vibrational fingerprints, including NO2, C–S, and C=C modes. The achievable enhancement is governed by probe integrity, surface cleanliness, polarization control, and environmental stability, all of which influence the efficiency of plasmonic confinement and field localization. The IR-neaSCOPE+TERS provides the mechanical stability and integrated Raman pathways required to support reproducible TERS measurements under ambient conditions.This measurement was realized with the IR-neaSCOPE+TERs.
Photoluminescence spectroscopy and correlative nano-imaging
The IR-neaSCOPE+TERs platform enables correlative nanoscopy by combining photoluminescence spectroscopy (PL) with high-performance AFM and near-field optical imaging. In this experiment, the measurement was performed simultaneously, with AFM in contact while illumination enabled the concurrent acquisition of AFM topography, tip-scattered near-field signals (VIS-SNOM), and Raman or PL maps. This integrated workflow provides a unified spatial reference and forms the nano-PL approach that connects structural, optical, and electronic contrast within a single scan.
A WSe2/MoS2 heterostructure served as the model system. PL highlights regions of interest and resolves mono- and interlayer excitons, while AFM provides 10–20 nm morphological resolution and complementary nanomechanical contrast. Concurrent Vis-SNOM imaging of the nearfield reveals nanoscale variations in stacking order, thickness, strain, dielectric response, and polaritonic behaviour beyond the diffraction limit.This measurement was realized with the IR-neaSCOPE+TERs.
Correlated TEPL and s-SNOM Imaging of Lateral WSe2/MoSe2 Heterostructures
By combining visible s-SNOM with integrated Raman and Photoluminescence (PL) spectroscopy and imaging, the IR neaSCOPE+TERS delivers a powerful platform for correlated multimodal nano characterization - ideal for quantum materials, optoelectronics, nanophotonics, and beyond.
The image showcases how the system acquires AFM, micrometer and nanometer resolved PL, as well as visible range s SNOM signals in parallel, thanks to fully separated detection channels. This simultaneous measurement ensures perfect spatial alignment and eliminates the need for sequential scans.A dedicated ultra-sensitive detection unit enables spectrally filtered PL imaging, providing diffraction-limited µ-PL overviews from the far-field channel and TEPL contrast from the tip-enhanced near-field contribution, which resolves sharp optical features at the lateral WSe2/MoSe2 interface. In parallel, visible s SNOM delivers nanoscale reflectivity and absorption contrast, revealing local optical constants with exceptional clarity. Together, these complementary modalities create a unified, nanoscale resolved picture of structure and optical response - unlocking material insights with nanoscale resolution.This measurement was realized with the IR-neaSCOPE+TERs.
Silicon Membrane Filters for Nanoplastic Analysis by nano-FTIR and Raman Spectroscopy
This study highlights the development and application of silicon membrane filters for detecting and analyzing nanoplastics (NPs) and small microplastics (SMPs) in seawater. The filters, engineered with precise lithographic and etching techniques, feature hexagonally arranged pores of 250 nm and 1 µm. Their innovative design ensures stability and compatibility with advanced analytical tools, including nano-FTIR for nanoscale particle analysis and Raman spectroscopy for larger particles. Tests using environmental samples, such as degraded polylactic acid (PLA) coffee lids and polyethylene (PE) and polystyrene (PS) particles, demonstrated the filters' effectiveness in separating particles for chemical identification. The filters' flat, reflective surfaces and optical markers enabled precise particle localization and seamless application of different analytical methods. The combination of nano-FTIR and Raman allowed comprehensive analysis, correlating well with reference data. This technology advances nanoplastic pollution research, offering robust tools for environmental monitoring, supporting ecological impact studies, and informing pollution mitigation efforts.
This measurement was realized with the IR-neaSCOPE+TERs.
Further reading:
Meyns et al., Analytical Methods 5, 2023
Nano-Interface 2D Alloys
Single-layer heterostructures exhibit striking quasiparticle properties and many-body interaction effects that hold promise for a range of applications. However, their properties can be altered by intrinsic and extrinsic defects, thus diminishing their applicability. Therefore, it is of paramount importance to identify defects and understand 2D materials’ degradation over time using advanced multimodal imaging techniques. Here we implemented a liquid-phase precursor approach to synthesize 2D in-plane MoS2–WS2 heterostructures exhibiting nanoscale alloyed interfaces and map exotic interface effects during photodegradation using a combination of hyperspectral tip-enhanced photoluminescence and Raman and near-field nanoscopy. Surprisingly, 2D alloyed regions exhibit thermal and photodegradation stability providing protection against oxidation. Coupled with surface and interface strain, 2D alloy regions create stable localized potential wells that concentrate excitonic species via a charge carrier funneling effect. These results demonstrate that 2D alloys can withstand extreme degradation effects over time and could enable stable 2D device engineering.
This measurement was realized with the IR-neaSCOPE+TERs.
Optoelectronic Properties of Nanosystems
The optoelectronic properties of nanoscale systems such as carbon nanotubes (CNTs), graphene nanoribbons and transition metal dichalcogenides (TMDCs) are determined by their dielectric function. This complex, frequency dependent function is affected by excitonic resonances, charge transfer effects, doping, sample stress and strain, and surface roughness. Knowledge of the dielectric function grants access to a material’s transmissive and absorptive characteristics. In this study s-SNOM technology is used for extracting local dielectric variations. In addition, s-SNOM measurements were correlated with spatially resolved PL spectroscopy and KPFM measurements.
s-SNOM in correlation with local photoluminescence (PL) is a useful tool for identifying and characterizing interlayer excitons. This novel method opens also applications in low-dimensional systems like carbon nanotubes and graphene nanoribbons.
This measurement was realized with the IR-neaSCOPE+TERs.
Combined TERS and s-SNOM
Tip-enhanced Raman spectroscopy (TERS) and scattering-type scanning near-field optical microscopy (s-SNOM) enable optical imaging with a spatial resolution far below the diffraction limit of light. Although s-SNOM records the elastically scattered light (yielding information about the local refractive index and absorption), in TERS, the Raman scattered light is detected, which provides, for example, chemical information. Here, we introduce a combined TERS and s-SNOM setup for correlative studies of tip-enhanced elastically scattered and Raman scattered light. Comparing s-SNOM and TERS signals, we demonstrate a qualitative correlation between the tip-enhanced elastic and tip-enhanced Raman scattered light. Thus, recording the tip-enhanced elastically scattered light enables a fast and reliable TERS alignment. Further, we demonstrate experimentally and by simulations that Pt-coated silicon tips can be used for TERS in gap-mode configuration.
This unique technological marriage could be employed for correlative analyses of structural, chemical, and photonic sample properties.
This measurement was realized with the IR-neaSCOPE+TERs.