Interdisciplinary research at the nanometer scale:
AFM + Confocal Raman + SNOM + TERS

General information

Integration of SPM and confocal microscopy/Raman scattering spectroscopy. Owing to Tip Enhances Raman Scattering it allows carrying out spectroscopy/microscopy with up to 10 nm resolution.

NTEGRA Spectra - AFM / CONFOCAL RAMAN & FLUORESCENCE / SNOM / TERS

Integration: The key to the new sciences

Change happens at interfaces and today’s most exciting changes in microscopy are happening where multiple technologies are interfaced together. NTEGRA Spectra is a prime example, uniting the full power of atomic force microscopy (AFM), confocal Raman and fluorescence microscopy and scanning near-field optical microscopy (SNOM) in one platform.

Simultaneous AFM and confocal Raman / Fluorescence imaging

NTEGRA Spectra supports most of the existing AFM modes (more than 30) providing comprehensive information about physical properties of the sample with nanometer scale resolution: local stiffness, elasticity, conductivity, capacitance, magnetization, surface potential and work function, friction, piezoresponse etc. Simultaneously with AFM, confocal Fluorescence and Raman measurements provide information about sample chemical composition, crystal structure and its orientation, presence of impurities and defects, macromolecular conformation, and so on.

Measurements can be performed either through upright or inverted light excitation geometries. The sample can be in a controlled atmosphere or in a liquid environment, all under controlled temperature. Complete Raman /fluorescence spectrum is recorded in each point of 2D / 3D scan with further powerful software analysis. Due to the excellent microscopy performance of the NTEGRA Spectra, 3D spectral distribution can be studied with the spatial resolution reaching the theoretical limit. 

Microscopy and spectroscopy at the molecular scale

Diffraction limited spatial resolution and weakness of Raman signal are the two major challenges in Raman microscopy. When using visible light, resolution of classical confocal microscopy does not go below 200 nm. The Raman signal is often only 1/millionth of the strength of a fluorescence signal. The new world of nanotechnology has disclosed a fascinating phenomenon: the electromagnetic field can be strongly enhanced near nanometer-scale metal asperities (“nano-antennas”).

The resulting effects are called Surface Enhanced Raman Scattering (SERS) and, when done in conjunction with an SPM tip, one can get Tip-Enhanced Raman Scattering (TERS).

By using a specially prepared sharp needle tip, NTEGRA Spectra can multiply the Raman signal strength by a few orders of magnitude from a precisely scanned, localized spot on the surface several nanometers in diameter. Even single molecules can be detected and recognized by their spectra. Lateral resolution of Raman (TERS) and fluorescence maps is no longer limited by light diffraction and can be less than 15 nm.

Different configuration of AFM with confocal Raman/Fluorescence microscope

Upright A unique configuration for simultaneous AFM - Raman - TERS* and SNOM imaging of opaque samples *TERS: Tip Enhanced Raman Scattering, Tip Enhanced Fluorescence etc.
Inverted Optimized for simultaneous AFM - Raman - TERS* and SNOM imaging of samples on transparent substrates (living cells, nanoparticles etc.) *TERS: Tip Enhanced Raman Scattering, Tip Enhanced Fluorescence etc.
Side illumination option Used to facilitate TERS* measurements on opaque samples *TERS: Tip Enhanced Raman Scattering, Tip Enhanced Fluorescence etc.
Fiber Scanning Near-field Optical Microscopy (SNOM) SNOM techniques based on on quartz fiber.
Cantilever Scanning Near-field Optical Microscopy (SNOM) SNOM techniques based on cantilevers with aperture.

•     Atomic Force Microscopy ( > 30 modes )
•     Confocal Raman / Fluorescence / Rayleigh Microscopy
•     Scanning Near-Field Optical Microscopy ( SNOM / NSOM )
•     Optimized for Tip Enhanced Raman and Fluorescence (TERS, TEFS, TERFS) and scattering SNOM (s-SNOM)

New era of integration 
Optical AFM (NT-MDT) + Raman spectrometer (Renishaw) = Join the best technologies in one system

HybriD Mode™

Ntegra Spectra equipped with new electronics and software allows to combine a recently developed innovative HybriD Mode™ (HD-AFM™ Mode) for nanomechanical proprieties and Raman for chemical imaging of exactly the same area within single measurement session.

Stiffness of HDPE/LDPE polymer sandwich cut by microtome	Overlap of Raman maps: HDPE (red), LDPE (blue)	AFM topography

Working principle

Modes:

• AFM (mechanical, electrical, magnetic properties, nanomanipulation etc.)
• White Light Microscopy and Confocal Laser (Rayleigh) Imaging
• Confocal Raman Imaging and Spectroscopy
• Confocal Fluorescence Imaging and Spectroscopy
• Scanning Near-Field Optical Microscopy (SNOM)
• Tip Enhanced Raman and Fluorescence Microscopy (TERS, TEFS, TERFS)

Controlled environment:

• Temperature
• Humidity
• Gases
• Liquid
• Electrochemical environment
• External magnetic field

Applications

• Graphene, carbon nanotubes and other carbon materials
• Semiconductor devices
• Nanotubes, nanowires, quantum dots and other nanoscale materials
• Polymers
• Optical device characterization: semiconductor lasers, optical fibers, waveguides, plasmonic devices
• Investigation of cellular tissue, DNA, viruses and other biological objects
• Chemical reaction control

Graphene flakes	Ni foil	PC-PVAC film	MoO3
30x30 um	20x20 um	30x30 um	30x30 um

Specifications

AFM-Raman measurements can run in air, in controlled atmosphere or in liquid — all with variable temperature (for Inverted configuration)

Some features listed are optional — not included into basic system configuration
* NT-MDT AFM can be integrated with Renishaw inVia or with NT-MDT spectrometer. Specifications are given for the latter. Renishaw specifications can be found at www.renishaw.com/AFM-Raman
** Exact value of spectral resolution highly depends on how “resolution” is defined