title: Rapid detection of multiple foodborne pathogens using a nanoparticle-functionalized multi-junction biosensor.
abstract: Real-time identification of multiple bacterial pathogens in food is urgently needed to ensure food safety. Although rapid and sensitive detection methods offering simplicity, accuracy, and multiplexity are highly desirable for industrial food applications, the development of a biosensor that meets all criteria remains a challenge. In this study, a single walled carbon nanotube- (SWCNT) based multi-junction sensor was designed for potential multiplexed detection of foodborne pathogens. Gold tungsten wires (Ø: 50 μm) coated with polyethylenimine (PEI) and SWCNTs were aligned to form a 2 × 2 junction array, functionalized with streptavidin and biotinylated antibodies specific for Escherichia coli K-12 and Staphylococcus aureus. Electric current (I) measurements in response to target binding events in pure serial diluted samples of E. coli and S. aureus at each junction within the 2 × 2 array were monitored to create calibration curves. An inverse correlation between I signals and bacterial concentrations was observed. Changes in I (∆I) were also calculated to reduce background noise and emphasize the SWCNT-based sensor's response to the biorecognition reactions between antibody and antigens. A linear regression was observed for both the E. coli and S. aureus functionalized array sensors, R(2)=0.978 and R(2)=0.992, in range of 10(2)-10(5)CFU/mL. The calibration curves were used to evaluate the sensor's multiplexing capabilities to detect E. coli and S. aureus in 10 µL and 100 µL batch microbial cocktail samples.Isignal responses exhibited similar measurement trends indicating that the developed SWCNT-based multi-junction biosensor has potential for sensitive, simple, and multiplexed applications.
authors.affiliation: Department of Human Nutrition, Food, and Animal Sciences, University of Hawaii, 1955 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Kara
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Human Nutrition, Food, and Animal Sciences, University of Hawaii, 1955 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Won
authors.initials: W
authors.lastname: Choi
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu, HI 96822, USA.
authors.forename: Inae
authors.initials: I
authors.lastname: Lee
authors.affiliation: Department of Biosystems Machinery Engineering, Chungnam National University, Daejeon, South Korea.
authors.forename: Byoung-Kwan
authors.initials: BK
authors.lastname: Cho
authors.affiliation: Department of Human Nutrition, Food, and Animal Sciences, University of Hawaii, 1955 East-West Road, Honolulu, HI 96822, USA. Electronic address: soojin@hawaii.edu.
authors.forename: Soojin
authors.initials: S
authors.lastname: Jun
mesh_terms: D001419:Bacteria / Q000302:isolation & purification*; D003199:Computer Systems; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000295:instrumentation*; D046228:Microarray Analysis / Q000295:instrumentation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D037742:Nanotubes, Carbon
keywords: Detection; Multi-function; Multiplexing; Pathogens