Selected applications of CPEs in biological species and pharmaceuticals compounds analysis using SWV.

Analyte	Modifier	Linear range	Detection limit	Ref.
Glutathione	N-(4-Hydroxyphenyl)-3,5-dinitrobenzamide-FePt/carbon nanotube (NHPDA/FePt/CNTs)	0.004–340 μM	1.0 nM	121
Glutathione	MgO/SWCNTs/2-chloro-N′-[1-(2,5-dihydroxyphenyl) methylidene]aniline (2-CDHPMA)	0.05–700.0 μM	10 nM	123
Glutathione	Ag–ZnO nanoplates/2-chlorobenzoyl ferrocene (2-CBF)	5.0 × 10−8 to 2.0 × 10−4 M	20.0 nM	124
Glutathione	Ethynylferrocene (EF)/NiO/MWCNT nanocomposite	0.01–200 μM	0.006 μM	125
Dopamine	CdTe quantum dots	7.5 × 10−8 to 6.0 × 10−4 M	2.1 × 10−8 M	140
Norepinephrine	ZnO/CNTs nanocomposite/ionic liquid (1,3-dipropylimidazolium bromide) (ZnO/CNTs/IL)	5.0 × 10−8 to 4.5 × 10−4 M	2.0 × 10−8 M	146
Levodopa	Graphene nanosheets, 1-(4-bromobenzyl)-4-ferrocenyl-1H-[1,2,3]-triazole (1,4-BBFT) and hydrophilic ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate)	5.0 × 10−8 to 8.0 × 10−4 M	1.5 × 10−8 M	152
Levodopa	Graphite oxide (GrO) and β-cyclodextrin (CD)	1.0–20 μM	0.065 μM	153
Levodopa	Graphene/ethyl 2-(4-ferrocenyl-[1,2,3]triazol-1-yl)acetate (EFTA)	0.2–0.4 mM	0.07 μM	154
Tyrosine	Reduced graphene oxide (rGO)/zinc oxide nanocomposite	0.1–400 μM	0.07 μM	161
d-Penicillamine	TiO2 nanoparticles/quinizarine (QZ)	0.8–140.0 μM	0.76 μM	166
Isoproterenol	5-Amino-3′,4′-dimethyl-biphenyl-2-ol (5ADB)/carbon nanotube	4.0 × 10−7 to 9.0 × 10−4 M	2.0 × 10−7 M	168
Methyldopa	Multiwalled carbon nanotubes (MWCNT)/p-chloranil	0.5–165.5 μM	0.2 μM	172
Methyldopa	5-Amino-2′-ethyl-biphenyl-2-ol (5AEB)/carbon nanotubes (CNTs)	0.1–210.0 μM	48.0 nM	173