Table 3 Characterization techniques and limitations
Technique | Main role | Limitations | Sensitivity | Ref. |
---|---|---|---|---|
Ultraviolet-visible spectroscopy (UV-vis) | Concentration and shape of NPs can be measured | Only for liquid samples | UV-visible regions 200–800 nm | [22] |
Fourier transform infrared spectroscopy (FTIR) | Nature of bonds and functional groups can be determined | Structure and size of NPs cannot be measured | 20 Å–1 μm | [22] |
X-ray diffraction (XRD) | Size and crystallinity of nanoparticles can be measured | Composition of NPs and plasmon cannot be found | 1 nm | [36] |
Scanning electron microscopy (SEM) | Shape and size of nanostructures can be determined | Samples must be solid and cannot detect elements with atomic number < 11 | < 1 nm | [115] |
Field emission scanning electron microscopy (FESEM) | All structural and morphological investigations are carried out by this technique | Does not give a concentration of NPs | < 1 nm | [117] |
Transmission electron microscopy (TEM) | Shape and size of nanostructures can be determined | Particles with size < 1.5 nm cannot be determined | < 1.5 nm | [92] |
Particle size analysis (PSA) | Measured the distribution of size in the sample of solid or liquid particulate materials | – | 1 nm–1 μm | |
Malvern Zetasizer (MZS) | Measured the size of NPs, zeta potential, and protein mobility | In nanorange | – | [58] |
Energy-dispersive X-ray spectroscopy (EDX/EDS) | Composition of NPs can be analyzed | Particles with size < 2 nm cannot be analyzed | < 2 nm | |
Nanoparticle tracking analysis (NTA) | Visualize and measure particle size, concentration, and fluorescent properties of a nanoparticle | – | 30–10 nm | [62] |
Small-angle X-ray scattering (SAXS) | Size and shape conformation | Lower resolution range | 50–10 Å | [116] |
X-ray reflectometry (XRR) | Determination of thickness, density, and roughness | Layer thickness 0.1–1000 nm | – | [116] |
X-ray fluorescence spectroscopy (XRF) | Chemical composition and concentration can be measured | Limited in their ability to measure precisely and accurately | – | [76] |
X-ray photoelectron spectroscopy (XPS) | Elemental composition of nanoparticles can be analyzed | Decomposition of samples occurred | 3–92 nm | [78] |
Brunauer-Emmett-Teller analysis (BET) | Specific surface area is measured | 0.35–2 nm | [76] | |
Selected area electron diffraction (SAED) | Technique that can be performed inside a TEM | Cannot be recommended for quantitative identification techniques | – | [76] |
Atomic force microscopy (AFM) | Particle size and characterization | For gas and liquid samples | 1 nm–8 μm | [88] |