Table 15.1.

Nanosensors Used for Detection of Pathogens

Analyte	Nanomaterial	Detection Method	Detection Limits	References
Bacilli
Campylobacter jejuni	Lectin immobilized on gold surface of quartz crystal electrode	QCM	Reusable, limit of detection 103 cells within 30 min	Safina et al. (2008)
E. coli O157:H7	Core-shell Cu/AuNPs with anti-E. coli Ab	Anodic-stripping voltammetry	Detection limit is 30 CFU/mL within a time span of 2 h	Zhang et al. (2009)
	Magnetic nanobeads	Impedance spectroscopy	45 log CFU/g in freshly ground beef, assay time 35 min	Varshney et al. (2005)
	Ab immobilized gold-coated on QCM	QCM with dissipation monitoring	Log–log linear working range 107–109 cells/mL	Poitras and Tufenkji (2009)
	Anti-E.coli Ab immobilized on PEG alkanethiol monolayers on SPR	Sandwich assay SPR immunosensor	Detection limit 106 CFU/mL, highly specific against Salmonella enteritidis	Subramanian et al. (2006)
	Sugar attached to iron-oxide NPs	Fluorescent staining	Can isolate up to 88% of E. coli within 45 min	El-Boubbou et al. (2007)
	Ab coated on iron-oxide NPs	Optic detection using FTIR/portable mid-IR	104–105 CFU/mL in 2% milk and spinach extract	Ravindranath et al. (2009)
S. aureus, Vibrio parahaemolyticus, and S. typhimurium	Multicolor upconversion NPs (rare-earth ions) coupled with aptamers attached to magnetic NPs	Magnetic NPs used for immuneseparation with aptamers followed by visible luminescence	25 CFU/mL for S. aureus 10 CFU/mL for V. parahaemolyticus 15 CFU/mL for S. typhimurium	Wu et al. (2014)
S. typhimurium and S. aureus	AuNPs labeled with Raman reporter molecules	Raman scattering	103 CFU/mL in spinach wash and peanut butter emulsion	Zhuyi et al. (2011)
S. typhimurium	Protein G-coated 11-mercaptoundecanoic acid monolayer on gold surface	SPR	102–109 CFU/mL	Oh et al. (2004)
S. typhimurium, Shigella flexneri, and E. coli O157:H7	Combination of magnetic NPs and Ab-conjugated semiconductor QD	Magnetic NPs immobilized with Ab and quantified by fluorescence	10–3 CFU/mL within 2 h in food matrix protein in high concentration decreased sensitivity of the method	Zhao et al. (2009)
Salmonella	Anti-Salmonella Ab immobilized to QD	Fluorescence at 415 nm UV	4 × 103 CFU/mL in food extracts	Kim et al. (2013)
S. aureus	AuNPs immobilized with anti-S. aureus Ab	Magnetic beads enhance capture of S. aureus from milk matrix florescence of gold quantified	Assay time 40 min, low sensitivity with detection limit of 5 log CFU/mL	Sung et al. (2013)
Viruses
Cauliflower mosaic virus	Lead sulfide NPs linked to cauliflower mosaic virus 35S oligonucleotide	Sensitive differential pulse anodic stripping voltammetric	Detection limit was 4.38 × 10–12 M/L	Sun et al. (2008)
Tomato ring-spot virus and grapevine fan leaf virus	Mesoporous silicon	Change in electric parameters after adsorption	Effective virus size for detection was 50 nm	Vashpanov et al. (2008)
Spores
Bacillus anthracis spores	Polyaniline-coated magnetic NPs (100 nm)	Detection mechanism depend on capillary flow of captured spores	Limit of detection 4.2 × 102 spores/mL within 16 min	Pal and Alocilja (2009)
Bacillus thuringiensis spores	60-base aptamer conjugated to zinc-sulfide capped CdSe QD	Detects at 655 nm with no photo bleaching of QDs	Semiquantitative, specific and detects 1000 CFU/mL	Ikanovic et al. (2007)