Table 3 Summary of analytical techniques to conduct physico-chemical characterisation, monitor nanoparticle surface driven protein conformational changes and uptake of nanoparticles by cellular structures

Nanoparticle physical characterisation

Size and charge

Dynamic light scattering

Changes in the hydrodynamic diameter of NP upon binding to proteins

[1]

Analytical Ultracentrifugation

Changes in the hydrodynamic diameter of NP

[6]

Dissolution

Inductively coupled mass spectrometry

For detecting elemental composition of the nanomaterial

[90]

Shape and structure

X ray diffraction

Determination of crystalline structure

[38]

Electron microscopy

Visualisation of nanoparticle structure

Surface area

Braunauer Emmet Teller method

Measures specific surface area using adsorption of gas on the surface

[38]

De-agglomeration

Ultrasonication

Uses sound energy to disrupt large aggregates of NP

[36]

Nanoparticle protein interaction

Protein binding affinity

Isothermal calorimetry

To measure binding constant, thermodynamic parameters of NP-protein interactions

[2]

Fluorescence spectroscopy

Measures change in fluorescence spectra due to NP-protein interaction

[65]

UV–vis spectroscopy

Measures change in absorption spectra due to NP-protein interaction

[57]

Quartz crystal balance

Detects change in mass at the oscillating quartz surface due to NP-protein interaction

[91]

Surface Plasmon resonance

Detects change in oscillation of electrons on a metal surface due to NP-protein interaction

[92]

Atomic force microscopy

Gives surface profile of the nanomaterial

[93]

Fluorescence correlation spectroscopy

Binding characteristics depending on fluctuation in florescence

[94]

Nanoparticle surface induced protein structure changes

Protein structural changes after binding

Circular Dichroism spectroscopy

Measures changes in secondary structure of proteins depending on chiral properties of proteins

[61]

Fourier transformed infrared spectroscopy

Measures adsorption of amide bonds in the proteins to derive structural change

[43]

Raman spectroscopy

Studies molecular vibrations to predict structure

[52]

Nuclear Magnetic Resonance

Relies on magnetic properties of atomic nuclei to predict structure

[4]

Nanoparticle- Cellular interactions

NP uptake

Confocal microscopy

Visualization of fluorescent nanoparticles in vitro

[59]

Confocal micro Raman spectroscopy

[95]