Table 2.

Types of nanoparticles used for transport in plants and their places of introduction.

Type	NPs	Size (nm)	Plants	Introduction Site	Ref.
Metal or metalloid	Ag	1–10	Tomato	Roots	[47]
	Ag	10	Triticum aestivum	Roots	[48]
	Ag	20 ± 3	Linum usitatissimum, Lolium perenne, Hordeum vulgare	Roots	[49]
	Ag	20	Arabidopsis thaliana	Roots	[50]
	Ag	10	Phaseolus radiatus, Sorghum bicolor	Roots	[51]
	Ag	10–15	Lycopersicum esculentum	Roots	[52]
	Ag	27.3 ± 6	Populus deltoides, Arabidopsis thaliana	Roots	[53]
	Al	18	Brassica napus, Raphanus sativus, Lolium perenne, Lactuca sativa, Zea mays, Cucumis sativus	Roots	[54]
	Au	1–3	Oryza sativa	Roots	[55]
	Au	3.5 and 18	Nicotiana xanthi	Roots	[56]
	Au	6–10	Oryza sativa, Lolium perenne, Raphanus sativus, Cucurbita mixta	Roots	[57]
	Co	28	Tomato	Roots	[47]
	Ni	28	Tomato	Roots	[47]
	Si	14	Arabidopsis thaliana	Roots	[58]
	Zn	35	Brassica napus, Raphanus sativus, Lolium perenne, Lactuca sativa, Zea mays, Cucumis sativus	Roots	[54]
Metal or metalloid oxide	CeO2	25	Holcus lanatus, Diplotaxis tenuifolia	Roots	[59]
	CeO2	8	Glycine max	Roots	[60]
	CeO2	8 ± 1	Oryza sativa	Roots	[61]
	CeO2	20 ± 2	Solanum lycopersicum	Roots	[62]
	CeO2	6.6 ± 1; 25.2 ± 2	Cucumis sativus	Roots	[63]
	Fe3O4	20–30	Tomato	Roots	[47]
	Fe3O4	8	Cucurbita maxima	Roots	[64]
	SiO2	10–20	Chelidonium majus	Leaves	[65]
	SiO2	20	Cucumis sativus	Leaves	[66]
	TiO2	20	Tomato	Roots	[47]
	TiO2	20 ± 5	Triticum aestivum	Roots	[67]
	TiO2	27 ± 4	Cucumis sativus	Roots	[68]
	TiO2	27	Lycopersicum esculentum	Roots	[52]
	TiO2	2.8 ± 1	Arabidopsis thaliana	Roots	[69]
	ZnO	10	Glycine max	Roots	[60]
	ZnO	20 ± 5	Brassica napus, Raphanus sativus, Lolium perenne, Lactuca sativa, Zea mays, Cucumis sativus	Roots	[54]
Carbon-based	C	20	Zea mays	Roots	[70]
	Carbon nanotubes (CNT)	10–30	Cicer arietinum	Roots	[71]
	Multi-walled carbon nanotubes (MWCNT)	10–20	Brassica napus, Raphanus sativus, Lolium perenne, Lactuca sativa, Zea mays, Cucumis sativus	Roots	[54]
	MWCNT	6–9	Zea mays	Roots	[72]
	MWCNT	4–13	Lactuca sativa, Oryza sativa, Cucumis sativus, Amaranthus tricolor, Abelmoschus esculentus, Capsicum annuum, Glycine max	Roots	[73]
	MWCNT	30	Brassica juncea	Roots	[74]
	MWCNT	6–13	Triticum aestivum	Roots	[75]
	Single-walled carbon nanotubes (SWCNT)	20	Nicotiana benthamiana	Leaves	[76]
Semiconductor	3-mercaptopropionic acid (MPA) quantum dots (QDs)	4–5.4	Lemna minor	Leaves	[77]
	Cd-based QDs	1.9 and 2.4	Allium cepa	Roots	[78]
	CdSe/CdZnS QDs	19.5 ± 7	Populus deltoides	Roots	[79]
	CdTe QDs	4	Oryza sativa	Roots
	Glutathione (GSH) QDs	4–4.4	Lemna minor	Leaves	[77]
Polymeric	Chitosan	19–21	Oryza sativa	Roots	[80]
	Thiamine loaded chitosan	10	Cicer arietinum	Roots	[81]
Magnetic	Superparamagnetic iron oxide (SPION)	9	Glycine max	Roots	[82]