Green Nanobiotechnology: Factors Affecting Synthesis and Characterization Techniques

Table 1

Different techniques used for characterization of nanoparticles.

Type	Technique	Specific purpose	References
Formation of nanoparticle	Ultraviolet-visible spectrophotometry	Provide information regarding the size, structure, stabilization, and aggregation of nanoparticles	[9, 47]
Morphology and particle size	Transmission electron microscopy	Determine the shape, size (10^−10 m), morphology, and allographic structure of the nanoparticles	[1, 44]
	High-resolution transmission electron microscopy	Determine the arrangement of the atoms and their local microstructures, such as lattice fringe, glide plane, lattice vacancies and defects, screw axes, and surface atomic arrangement of crystalline nanoparticles	[60, 71]
	Scanning electron microscopy	Determine the morphology by direct visualization	[63, 64, 94]
	Atomic force microscopy	Determine the size information (length, width, and height) and other physical properties (such as morphology and surface texture)	[1, 6]
	Dynamic light scattering	Determine the particle size distribution	[6, 64, 69]
Surface charge	Zeta potential	Determine the stability and surface charge of the colloidal nanoparticles, as well as the nature of the materials encapsulated inside the nanoparticle or coated on its surface	[72]
	Fourier transform infrared spectroscopy	Characterize the nanoparticles to understand their functional groups and determine the emission, absorption, photoconductivity, or Raman scattering of a solid, liquid, or gas	[56, 64, 71]
	X-ray photoelectron spectroscopy	Determine the mechanism of the reaction that occurs on the surface of magnetic nanoparticles and the characteristics involved in the bonding of different elements involved, as well as confirming the structure and speciation of different elements present in the chemical composition of the magnetic nanoparticles	[71]
	Thermal gravimetric analysis	Confirm the formation of coatings such as surfactants or polymers to estimate the binding efficiency on the surface of magnetic nanoparticles	[71]
Crystallinity	X-ray diffraction	Identify and quantify various crystalline forms or elemental compositions of nanoparticles	[6, 47, 73]
Magnetic properties	Vibrating sample magnetometry	Evaluate the magnetization of magnetic nanoparticles	[71]
	Superconducting quantum interference device magnetometry	Determine the magnetic properties of the magnetic nanoparticles	[71]
Other techniques used in nanotechnology	Chromatography and related techniques	Separate nanoparticles on the basis of their affinity towards the mobile phase	[73, 81]
	Energy dispersive X-ray spectra	Identify the elemental composition of the nanoparticles	[56, 95]
	Field flow flotation	Separate different nanoparticles based on their magnetic susceptibility	[96]
	Filtration and centrifugation techniques	Fractionate the preparative size of the nanoparticles	[82–84]
	Hyperspectral imaging	Determine the type of nanoparticles, study the fate and transformation of these particles in water samples, and characterize the unique surface chemistry and functional groups added to the nanomaterial	[87]
	Laser-induced breakdown detection	Analyze the concentration and size of colloids	[88, 89]
	Mass spectrometry	Analyze fluorescent labeled nanoparticles	[90, 91]
	Small angle X-ray scattering	Investigate the structural characterization of solid and fluid materials in the nanometer range	[73, 81]
	X-ray fluorescence spectroscopy	Identify and determine the concentrations of elements present in solid, powdered, or liquid samples	[73, 81]