Table 2.

Classification of electrochemical biosensors employing labels for pathogen detection in terms of: target, working electrode, biorecognition element, electrochemical method, limit of detection, electrochemical probe, and label or secondary processing step. Abbreviations: quartz crystal microbalance (QCM), electrochemical impedance spectroscopy (EIS), cyclic voltommetry (CV), plaque-forming unit (PFU), colony-forming unit (CFU), indium tin oxide (ITO), carbon nanotube (CNT), magnetic bead (MB), nanoparticle (NP), differential pulse voltammetry (DPV), square wave voltammetry (SWV), anodic stripping voltammetry (ASV), hemagglutination units (HAU), and median tissue culture infectious dose (TCID₅₀).

Target Pathogen	Working Electrode	Biorecognition Element	Electrochemical Method & Probe	Limit of Detection	Secondary Binding Step	Reference
E. coli	ITO electrode	anti-E. coli	EIS; Fe(CN)63-/4-	6 × 105 cells/mL	antibody/ALP conjugate label for amplification	Yang and Li (2005)
V. cholerae	carbon/polystyrene electrode	polyclonal anti-V.cholerae	chrono-amperometry	105 cells/mL	antibody-ALP conjugate label for amplification	Rao et al. (2006)
E. coli	Au interdigitated microelectrode array	polyclonal anti-E. coli	EIS	2.67 × 106 cells/mL	antibody-coated MBs for separation	Varshney et al. (2007)
V. parahaemolytic	carbon electrode	anti-V. parahaemolytic	CV; thionine/hydrogen peroxide	7.37 × 104 CFU/mL	antibody/HRP conjugate label for transduction	Zhao et al. (2007)
E. coli	Au interdigitated microelectrode array	polyclonal anti-E. coli	EIS	7.4 × 104 CFU/mL	antibody-coated MBs for separation and amplification	Varshney and Li (2007)
E. coli	AuNPs on carbon electrode	monoclonal and polyclonal anti-E. coli	CV; ferrocenedicarboxylic acid/hydrogen peroxide	6 CFU/mL	polyclonal antibody/HRP conjugate label for amplification	Lin et al. (2008)
S. aureus	Au electrode	anti-S. aureus	amperometry; tetrathiafulvalene/hydrogen peroxide	370 cells/mL	antibody/HRP conjugate label for amplification	Escamilla-Gomez et al. (2008)
S. typhimurium	Au electrode	monoclonal anti-S. typhimurium	chrono-amperometry; tetramethylbenzidine dihydrochloride/hydrogen peroxide	21 CFU/mL	anti-S. typhimurium polyclonal antibody/HRP conjugate label for amplification	Salam and Tothill (2009)
S. typhimurium	graphite-epoxy composite electrode	polyclonal anti-S. typhimurium	amperometry	0.1 CFU/mL	primary antibody-coated MBs for separation, secondary antibody/HRP conjugate label for amplification	Liebana et al. (2009)
avian influenza virus (AIV) H5N1	Au interdigitated microelectrode array	monoclonal anti-AIV-H5	EIS	0.26 HAU/mL	antibody-coated MBs for separation	Wang et al. (2010)
Streptococcus pneumoniae	Au electrode	polyclonal anti-S. pneumoniae	amperometry; tetrathiafulvalene/hydrogen peroxide	1.5 × 104 CFU/mL	antibody-coated MBs for separation and bacteria immobilization, antibody/HRP conjugate label for amplification	Campuzano et al. (2010)
E. coli	carbon-graphite electrode	monoclonal anti-E. coli	CV	7 CFU/mL	antibody-coated MBs for separation, antibody/polyaniline label for amplification	Setterington and Alocilja (2011)
S. aureus	MBs on Au electrode	polyclonal anti-Protein A (S. aureus)	amperometry; tetrathiafulvalene/hydrogen peroxide	1 CFU/mL	antibody/Protein A/HRP conjugate for amplification	Esteban-Fernandez de Avila et al. (2012)
avian influenza virus (AIV) H5N1	Au interdigitated microelectrode array	monoclonal anti-AIV-H5, polyclonal anti-AIV-N1	EIS	103 EDI50/mL	anti-AIV-H5 monoclonal antibody- coated MBs for separation, red blood cell label for amplification	Lum et al. (2012)
E. coli	AuNPs/SiO2 nanocomposite on sulfhydryl chitosan/Fe(C2H5)2/C60 composite on carbon electrode	monoclonal anti-E. coli	CV; ferrocene	15 CFU/mL	antibody/glucose oxidase/Pt nanochain conjugate label for amplification	Li et al. (2013)
C. parvum	polypyrrole-coated carbon electrode	polyclonal anti-C. parvum	chrono-potentiometry; o-phenylenediamine/hydrogen peroxide	500 oocysts/mL	antibody/HRP conjugate label for amplification	Laczka et al. (2013)
L. monocytogenes	polymeric ion-selective membrane electrode	anti-L. monocytogenes InlA aptamer	potentiometry	10 CFU/mL	aptamer/protamine label for transduction	Ding et al. (2014)
avian influenza virus (AIV) H5N1	Au interdigitated electrode array	anti-AIVH5N1 aptamer	EIS	0.04 HAU/mL	aptamer-coated MBs for separation, Concanavalin A/glucose oxide-coated AuNP labels for amplification	Fu et al. (2014).
L. monocytogenes	interdigitated microelectrode array	monoclonal and polyclonal anti-L. monocytogenes	EIS	300 CFU/mL	monoclonal antibody-coated MBs for separation, polyclonal antibody-coated AuNP label for secondary binding amplification	Chen et al. (2015)
E. coli	carbon electrode	polyclonal anti-E.coli	chrono-amperometry	148 CFU/mL	primary antibody-coated MBs for separation, secondary antibody-coated AuNPs for amplification	Hassan et al. (2015)
avian influenza virus (AIV) H5N1	AuNPs on ITO microelectrode	polyclonal anti-AIVH5N1	ASV	10 pg/mL	antibody-coated MBs for separation and anodic stripping	Zhou et al. (2015)
E. coli	Au interdigitated microelectrode array	anti-E.coli	EIS; Fe(CN)63-/4-	100 CFU/mL	wheat germ agglutinin for amplification	Li et al. (2015)
E. coli	carbon electrode	monoclonal and polyclonal anti-E. coli	DPV	10 CFU/mL	monoclonal antibody-coated MBs for separation, polyclonal antibody-coated AuNP label for amplification	Wang and Alocilja (2015)
norovirus	nanostructured Au microelectrode	concanavalin A lectin, polyclonal anti-norovirus	CV, EIS; Fe(CN)63-/4-	35 copies/mL	antibody-ALP conjugate label for amplification	Hong et al. (2015)
Legionella pneumophila	carbon electrode	polyclonal anti-L. pneumophila	amperometry; hydroquinone/hydrogen peroxide	10 CFU/mL	primary antibody- coated MBs for separation, secondary antibody/HRP conjugate label for amplification	Martin et al. (2015)
S. aureus	carbon electrode	anti-S.aureus aptamer	ASV	1 CFU/mL	primary aptamer-coated MBs for separation, secondary aptamer-coated AgNP label for anodic stripping	Abbaspour et al. (2015)
L. monocytogenes	Au interdigitated microelectrode array	monoclonal and polyclonal anti-L. monocytogenes	EIS	160 CFU/mL	monoclonal antibody-coated MBs for separation, polyclonal antibody-coated AuNP label for amplification	Chen et al. (2016b)
E. coli	Au interdigitated microelectrode array	polyclonal anti-E. coli	CV, amperometry	52 CFU/mL	antibody-coated, AuNP/glucose oxidase-modified MBs for separation and amplification	Xu et al. (2016a)
E. coli	Au interdigitated microelectrode array	anti- E. coli	EIS	100 CFU/mL	antibody-coated MBs for separation, antibody/glucose oxidase conjugate for amplification	Xu et al. (2016b)
S. typhimurium	Au interdigitated microelectrode array	monoclonal anti-S. typhimurium	EIS	100 CFU/mL	antibody-coated MBs for separation, antibody/glucose oxidase conjugate label for amplification	Xu et al. (2016b)
E. coli	chitosan/CNT composite on carbon electrode	polyclonal anti-E. coli	CV; thionine/hydrogen peroxide	50 CFU/mL	secondary antibody/HRP conjugate label enzyme-assisted reduction reaction	Gayathri et al. (2016)
S. typhimurium	carbon electrode	polyclonal and monoclonal anti-S. typhimurium	DPV	100 cells/mL	polyclonal antibody- coated MBs for separation, monoclonal antibody- coated AuNP label for amplification	Afonso et al. (2016)
E. coli	Au electrode	anti-E. coli	EIS; Fe(CN)63-/4-	100 CFU/mL	AuNP label for amplification	Wan et al. (2016)
L. monocytogenes	Au interdigitated electrode array	polyclonal anti-L. monocytogenes	EIS	1.6 × 103 CFU/mL	antibody-coated MBs for separation, antibody-coated AuNP label for amplification	Wang et al. (2017)
E. coli	Au microelectrode	monoclonal anti-E. coli	LSV	39 CFU/mL	antibody-coated MBs for separation, antibody/AuNP/nucleotide/CdSNP conjugate label for amplification	Li et al. (2017)
V. cholerae	Au microelectrode	polyclonal anti-V. cholerae	LSV	32 CFU/mL	antibody-coated MBs for separation, antibody/AuNP/nucleotide/PbSNP conjugate label for amplification	Li et al. (2017)
avian influenza virus (AIV) H5N1	Au electrode	anti-AIVH5N1, concanavalin A lectin	CV	0.367 HAU/mL	Concanavalin A- coated MB labels for amplification	Zhang et al. (2017)
human influenza A virus H9N2	carbon electrode	polyclonal anti-influenza A virus M2 protein, fetuin A	chrono-amperometry	16 HAU	antibody-coated MBs for separation, fetuin A-coated AuNP label for amplification	Sayhi et al. (2018)
human enterovirus 71 (EV71)	AuNPs on ITO electrode	monoclonal anti-EV71	CV, EIS, colorimetry; Fe(CN)63-/4-	10 pg/mL	antibody/HRP-coated MB labels for amplification	Hou et al. (2018)
E. coli	Ag interdigitated microelectrode array	melittin peptide	EIS	1 CFU/mL	MLT-coated MBs used for separation and bacteria immobilization	Wilson et al. (2019)
S. typhimurium	Ag interdigitated electrode array	melittin peptide	EIS	10 CFU/mL	MLT-coated MBs used for separation and bacteria immobilization	Wilson et al. (2019)
S. aureus	Ag interdigitated electrode array	melittin peptide	EIS	110 CFU/mL	MLT-coated MBs used for separation and bacteria immobilization	Wilson et al. (2019)
Middle East respiratory syndrome corona virus (MERS-CoV)	AuNPs on carbon electrode	MERS-CoV antigen-antibody complex	SWV; Fe(CN)63-/4-	400 fg/mL	MERS CoV-antibody complex	Layqah and Eissa (2019)