Table 2.

Electrochemical biosensors in Parkinson’s disease: main achievement.

Authors	Year	Type of Biosensor	Chemical Process	Experiment	Fluid	Biomarker	LODs
Ali et al. [43]	2007	poly (anilineboronic acid)/carbon nanotube composit	Dopamine oxidation	In vitro	Blood	Dopamine	-
Bai and Jiang [44]	2013	Copper sulfide-decorated reduced graphene oxide composites	CuS/RGO composite-based reaction	In vitro	-	H2O2	-
Xu et al. [35]	2015	Cysteamine-graphene modified gold electrode nanocomposites	Carboxylic acid-induced covalent attachment	In vitro	Serum	α-synuclein	1.2 pM
Wang et al. [45]	2015	Gold Fe3O4 Platinum Graphene-based nanocomposites	Catalytic reaction of Pt RGO/AuFe3O4-GCE	In vitro	Normal and tumor cells	H2O2	0.1 μM
Oh et al. [46]	2017	Organic field-effect-transistor-type nonenzymatic biosensor	Dopamine oxidation	In vivo	ISF	L-Dopa	10 pM
Goud et al. [15]	2019	Orthogonal electrochemical/ biocatalytic hollow MN	Dopamine oxidation	In vivo/In vitro	ISF	L-Dopa	-
Nguyen et al. [47]	2019	Platinum-based nanocomposite	Glutamate oxidation	In vitro	Spinal cord sample	Glutamate	0.2–0.5 μM
Aziz et al. 2019 [48]	2019	LDHs and graphene-based nanocomposite	Dopamine oxidation	In vitro	Living cells	Dopamine	2.0 nM
Dong et al. [49]	2020	5-(1,2-dithiolan-3-yl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl) pent-anamide	One-step amide reaction	In vitro	Blood	H2O2	0.02 μM
Chang et al. [50]	2021	Nanobiosensor integrated with solid-phase microextractiontechnique	Dopamine oxidation	In vitro	Cytoplasm of single living cell	Dopamine	10 pM
Moon et al. [25]	2021	Wearable electrochemical platform	L-Dopa oxidation	In vivo/In vitro	Sweat/Blood	L-Dopa	-
Shi et al. [51]	2021	N-doped carbon nanorods and Au nanoparticles based biosensor	Dopamine oxidation	In vivo	Serum	Dopamine	-
Kudur-Jayaprakash et al. [40]	2021	Cetyl pyridinium bromide (CPB) modified carbon paste electrode (CPBMCPE) biosensor	Dopamine/Uric Acid-Voltammetric oxidation	In vivo	Urine	Dopamine/Uric Acid	38–42 μM

LOD: limit of detection.