. 2017 Apr 27;17(5):965. doi: 10.3390/s17050965

Table 2.

Multiplexed electrochemical immunosensors using barcode configurations.

Electrode	Label	Analyte	Immunoassay	Technique	Linear Range	LOD	Sample	Ref.
Cancer biomarkers
G/Au/GCE	THI (or Co or Fc or AQ)-Strept-Biotin-dsDNA/Strept-Biotin-Ab₂/AuNPs/SiO₂/Fe₃O₄	CEA, CA125, PSA, AFP	Sandwich-type; direct detection after conjugation	DPV	0.2–600 pg·mL⁻¹ CEA; 0.2–1000 pg·mL⁻¹ CA125; 0.2–800 pg·mL⁻¹ PSA; 0.2–800 pg·mL⁻¹ AFP	48 fg·mL⁻¹ CEA; 77 fg·mL⁻¹ CA125; 60 fg·mL⁻¹ PSA; 62 fg·mL⁻¹AFP	-	[6]
AuNPs/GCE	PVP/GS/PtPdNPs/HRP/AQ PVP/GS/PtPdNPs/HRP/THI	AFP, APT; DCP, AFP-L3, γ-GT, AFU	Sandwich-type; addition of H₂O₂	DPV	0.025–5.0 ng·mL⁻¹ AFP; 0.024–9.6 ng·mL⁻¹ APT; 0.032–3.2 UL⁻¹ DCP; 0.024–2.4 ng·mL⁻¹ AFP-L3; 1.0–9.5UL⁻¹ γ-GT; 1.2–9.0 UL⁻¹ AFU	0.008 ng·mL⁻¹ AFP; 0.0082 ng·mL⁻¹ APT; 0.01UL⁻¹ DCP; 0.008 ng·mL⁻¹ AFP-L3; 0.33 UL⁻¹ γ-GT; 0.4 UL⁻¹ AFU	serum	[12]
GCE (Hg)	PAMAM-CdS (or ZnS, or PbS)	CA125 CA15-3 CA19-9	Sandwich-type; direct detection of Cd, Zn and Ag	SWASV	0.01–50 U·mL⁻¹	0.005 U·mL⁻¹	serum	[13]
IL/rGO/GCE	PtNPs-Cu²⁺ PtNPs-Cd²⁺	AFP CEA	Sandwich-type; reduction of metal ions	DPV	0.05–200 ng·mL⁻¹	0.05 ng·mL⁻¹ AFP 0.002 ng·mL⁻¹ CEA	serum	[14]
AuNPs/Chit/GCE	CGS-PB; CGS-TB	CEA; AFP	Sandwich-type; direct detection	DPV	0.5–60 ng·mL⁻¹	0.1 ng·mL⁻¹ (CEA) 0.05 ng·mL⁻¹ (AFP)	serum	[33]
AuNPs/Chit/GCE	Chit/AuNPs/PB; Chit/AuNPs/Fc	CEA; AFP	Sandwich-type; direct detection	DPV	0.05–100 ng·mL⁻¹	0.02 ng·mL⁻¹ (CEA) 0.03 ng·mL⁻¹ (AFP)	serum	[34]
HAG/PANI/rGO/GCE	AuNPs/rGO/PB; AuNPs/rGO/PDDA/THI	CEA; AFP	Sandwich-type; direct detection	DPV	0.6–80 ng·mL⁻¹	0.12 ng·mL⁻¹ (CEA) 0.08 ng·mL⁻¹ (AFP)	serum	[35]
AuNPs/GCE	Fc/HRP THI/HRP	CEA AFP	Direct assay after addition of H₂O₂	DPV	0.01–50 ng·mL⁻¹	0.01 ng·mL⁻¹	serum	[36]
AuNPs/G/GCE	THI-HRP-NPG-MnO₂ Fc-HRP-NPG-MnO₂	CA-15-3 CA-125	Sandwich-type; addition of H₂O₂	SWV	0.01–50 U·mL⁻¹	3.5 mU·mL⁻¹ (CA-153) 4.1 mU·mL⁻¹(CA-125)	serum	[37]
PDPMT-Cl-Chit/GCE	THI-Fe₃O₄NPs Fca-Fe₃O₄NPs	SCC-Ag CEA	Sandwich; direct detection	DPV	0.01–10 ng·mL⁻¹	4 pg·mL⁻¹ (SCC-Ag) 5 pg·mL⁻¹ (CEA)	serum	[38]
CD/G/GCE	CD/Fc/G CD/THI/G	CEA AFP	Sandwich-type with HRP-Ab₂ and H₂O₂ detection	DPV	0.003–40 ng·mL⁻¹ CEA 0.001–60 ng mL⁻¹ AFP	0.8 pg·mL⁻¹ CEA 0.5 pg·mL⁻¹ AFP	serum	[39]
rGO/THI (or PB)/AuNPs/ITO	-	CEA AFP	Direct detection of of THI or PB	SWV	0.01–300 ng·mL⁻¹	0.650 pg·mL⁻¹ CEA 0.885 pg·mL⁻¹ AFP	serum	[40]
TB (orPB)/AuNPs/TCCRMSs/FTO	-	CEA NSE	Direct; detection of TB or PB	SWV	2–25 ng·mL⁻¹	0.11 ng·mL⁻¹ CEA 0.08 ng·mL⁻¹ NSE	serum	[41]
HOOC-MBs/SPCE	ACTP/AuNPs ATLP/AuNPs	p53¹⁵, p53³⁹²	Sandwich-type; detection of metals	SWV	1–20 ng·mL⁻¹ (p53¹⁵) 0.5–20 ng·mL⁻¹ (p53³⁹²)	0.5 ng·mL⁻¹ (p53¹⁵) 0.2 ng·mL⁻¹ (p53³⁹²)	serum	[42]
GCE (Bi)	G/AuNPs-r-Apo-Cd G/AuNPs-r-Apo-Pb	AFP CEA	Sandwich-type; detection of metals	SWASV	0.001–5 ng·mL⁻¹	0.3 pg·mL⁻¹ AFP; 0.35 pg·mL⁻¹ CEA	serum	[43]
rGO	CdSeTe@CdS Ag NCs	Bcl-2 Bax	Sandwich-type; direct detection of Cd and Ag	SWASV	1–250 ng·mL⁻¹	0.5 fmol	leukemiaK562 cells	[44]
Chit/MWCNTs/GCE	OMC-Zn OMC-Cd	AFP HER-2	Sandwich-type; oxidation of metal ions	DPV	0.001–150 ng·mL⁻¹	0.6 pg·mL⁻¹ AFP 0.35 pg·mL⁻¹ HER-2	serum	[45]
GCE	Envision^TM-CdS (or PbS or AuNPs)	AFP CEA CA19-9	Sandwich-type; detection of metals	DPASV DPCSV	0.001–50 ng·mL⁻¹ AFP; CEA; 0.005–100 ng·mL⁻¹ CA19-9	0.02 pg·mL⁻¹ AFP; 0.05 pg·mL⁻¹ CEA; 0.3 pg·mL⁻¹ CA19-9	serum	[46]
Glu/Chit/AuNPs/AuE	BSA/AuNPs-Pb²⁺ BSA/AuNPs-Cd²⁺	CEA AFP	Sandwich-type; reduction of metal ions	DPV	0.01–50 ng·mL⁻¹	4.6 pg·mL⁻¹ CEA 3.0 pg·mL⁻¹ AFP	serum	[47]
AuNPs/AuE	AuNPs@MWCNTs-Pb²⁺ AuNPs@MWCNTs-Cd²⁺	CEA AFP	Sandwich-type; reduction of metal ions	SWV	0.01–60 ng·mL⁻¹	3.0 pg·mL⁻¹ CEA 4.5 pg·mL⁻¹ AFP	serum	[48]
AuNPs/rGO/Chit	AgNPs/THI/CNSs AgNPs/CNSs	CEA AFP	Sandwich-type; direct detection	DPV	0.01–80 ng·mL⁻¹	2.8 pg·mL⁻¹ CEA 3.5 pg·mL⁻¹ AFP	serum	[49]
IL/rGO/PSS/GCE	CGN-THI CGN-DAP CGN-Cd²⁺	CEA PSA AFP	Sandwich-type; direct detection	SWV	0.01–100 ng·mL⁻¹	2.7 pg·mL⁻¹ CEA 4.8 pg·mL⁻¹ PSA 3.1 pg·mL⁻¹ AFP	serum	[50]
AuNPs/AuE	TiO₂/Nf- Co(dcbpy)₃²⁺ TiO₂/Nf- MB	CA15-3 CA19-9	Sandwich-type; direct detection	DPV	5–100 U·mL⁻¹ CA15-3 1–100 U·mL⁻¹ CA19-9	0.3 UmL⁻¹ CA15-3 1.6 UmL⁻¹ CA19-9	serum	[51]
AuNPs/PAPT/GCE	poly(VFc-ATP) AuNPsPOPD/AuNPs	AFP CEA	Sandwich-type; direct detection	DPV	0.01–100 ng·mL⁻¹	0.003 ng·mL⁻¹ AFP 0.006 ng·mL⁻¹ CEA	serum	[52]
AuNPs/G/GCE	PS-Cd²⁺ PS-Fc	IL-6 IL-17	Sandwich-type; direct detection	SWV	1–1000 pg·mL⁻¹ IL-6 2–1000 pg·mL⁻¹ IL-17	0.5 pg·mL⁻¹ 1 pg	serum	[53]
Protein A/Nafion/GCE	GS/AuNPs-THI (or Cobpy)₃³⁺ or Fc)	AFP CEA SS2	Sandwich.type; direct detection	DPV	0.016–50 ng·mL⁻¹ AFP 0.010–50 ng·mL⁻¹CEA 0.012–50 ng·mL⁻¹ AFP	5.4 pg·mL⁻¹ AFP 2.8 pg·mL⁻¹ CEA 4.2 pg·mL⁻¹ AFP	-	[54]
AuNPs/PEI/PTCA/GCE	Au@PBNPs/O-GS-Strept-AP; Au@NiNPs/O-GS-Strept-AP	fPSA PSA	Sandwich-type; AA-P addition	DPV	0.02–10 ng·mL⁻¹ fPSA 0.01–50 ng·mL⁻¹ PSA	6.7 pg·mL⁻¹ 3.4 pg·mL⁻¹	serum	[55]
MWCNTs/GCE	AA liposome UA liposome	NSE ProGRP	Sandwich-type, direct detection	LSV	50–1000 pg·mL⁻¹	5.0 pg·mL⁻¹ NSE 100 pg·mL⁻¹ ProGRP	serum	[56]
AuNPs/IL/rGO/GCE	Cd (or Pb or Cu) AlgNBs	AFP CEA PSA	Sandwich-type; direct detection	DPV	0.01–100 ng·mL⁻¹	0.01 ng·mL⁻¹AFP 0.0086 ng·mL⁻¹CEA 0.0075 ng·mL⁻¹PSA	serum	[57]
GCE (Bi)	PLL/AuNPs/Cd-Apo (or Pb-Apo)	AFP CEA	Sandwich-type; direct detection	ASSWV	0.01–50 ng·mL⁻¹	4 pg·mL⁻¹	serum	[58]
Chit/AuNPs/GCE	GA/Chit/pAA NSs-Cu²⁺ (or Cd²⁺ or Zn²⁺)	CEA CA19-9 CA125 CA242	Sandwich-type; direct detection	SWV	0.1–100 ng·mL⁻¹ CEA 1–150 U·mL⁻¹ CA 19-9, CA125,CA242	0.02 ng·mL⁻¹ CEA 0.4 U·mL⁻¹ CA19-9 0.3 U·mL⁻¹ CA125 0.4 U·mL⁻¹ CA242	serum	[59]

Abbreviations: AA, ascorbic acid; AA-P, ascorbic acid 2-phosphate; ACTP, apoferritin templated cadmium phosphates; AFP, alpha fetoprotein; AFP-L3, lens culinaris (LCA)-reactive fraction of AFP; AFU, alpha-L-fucosidase; AgNCs, silver nanoclusters; Alg, alginate; Apo, apoferritin; APT, abnormal prothrombin; ATLP, apoferritin templated lead phosphates; AU, uric acid; Bax, Bcl-2 associated X protein; Bcl, B-cell lymphoma; CEA, Chit, chitosan; CGN, carbon-gold nanocomposite; CGS, carboxyl graphene nanosheet; CNS, carbon nanospheres; DCP, des-c-carboxy prothrombin; Fc. ferrocene; fPSA, free-prostate specific antigen; FTO, fluorine-doped tin oxide; G, graphene; γ-GT, γ-glutamyltranspeptidase; GCE, glassy carbon electrode; O-GS, onion-like graphene sheet; HER-2, human epidermal growth factor receptor type-2; HRP, horse-raddish peroxidase; IL, ionic liquid; NPG, nanoporous gold; NSE, neuron-specific enolase; OMC, ordered mesoporous carbon; pAA, polyacrylic acid; PATP, poly(2-aminothiophenol); PB, Prussian blue; PDPMT-Cl, poly(3-(1,1-o-dimethyl-4-piperidine-methylene)thiophene-2,5-diylchloride); PEI, polyethyleneimine; PLL, poly-L-lysine; POPD, poly(o-phenylenediamine); ProGRP, pro-gastrin-releasing peptide; PTCA, 3,4,9,10-perylenetetracarboxylic acid; SS2, streptococcus suis serotype 2; TB, toluidine blue; TCCMRSs, tryptophan and caffeic acid-based resin microspheres; TB, toluidine blue; THI, thionine; UA, uric acid; VFc-ATP, vinyl ferrocene-2-aminothiophenol.