The Development of a Portable SPR Bioanalyzer for Sensitive Detection of Escherichia coli O157:H7

Abstract

The purpose of this study was to develop a portable surface plasmon resonance (SPR) bioanalyzer for the sensitive detection of Escherichia coli O157:H7 in comparison with an enzyme-linked immunosorbent assay (ELISA). The experimental setup mainly consisted of an integrated biosensor and a homemade microfluidic cell with a three-way solenoid valve. In order to detect Escherichia coli O157:H7 using the SPR immunoassay, 3-mercaptopropionic acid (3-MPA) was chemisorbed onto a gold surface via covalent bond for the immobilization of biological species. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) were used as crosslinker reagents to enable the reaction between 3-MPA and Escherichia coli O157:H7 antibodies by covalent –CO–NH– amide bonding. The experimental results were obtained from the Escherichia coli O157:H7 positive samples prepared by 10-, 20-, 40-, 80-, and 160-fold dilution respectively, which show that a good linear relationship with the correlation coefficient R of 0.982 existed between the response units from the portable SPR bioanalyzer and the concentration of Escherichia coli O157:H7 positive samples. Moreover, the theoretical detection limit of 1.87 × 103 cfu/mL was calculated from the positive control samples. Compared with the Escherichia coli O157:H7 ELISA kit, the sensitivity of this portable SPR bioanalyzer is four orders of magnitude higher than the ELISA kit. The results demonstrate that the portable SPR bioanalyzer could provide an alternative method for the quantitative and sensitive determination of Escherichia coli O157:H7 in field.

Simultaneous Detection of Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes at a Very Low Level Using Simultaneous Enrichment Broth and Multichannel SPR Biosensor

“…In recent years, many studies have reported the application of SPR biosensors in the detection of O157:H7, S. enteritidis , and L. monocytogenes (Nanduri and others ; Liu and others ; Wang and others ). Nanduri and others () applied a SPREETA3 TM biosensor for the detection of L. monocytogenes using phage‐displayed antibody and the detection limit for L. monocytogenes in buffer was estimated to be 2.0 × 10 6 CFU/mL.…”

“…Nanduri and others () applied a SPREETA3 TM biosensor for the detection of L. monocytogenes using phage‐displayed antibody and the detection limit for L. monocytogenes in buffer was estimated to be 2.0 × 10 6 CFU/mL. Wang and others () developed a portable SPR biosensor for sensitive detection of O157:H7 and the theoretical detection limit of 1.87 × 10 3 CFU/mL was calculated from the positive control samples. The detection format used with SPR biosensor in both studies is direct detection, which may contribute to the high detection limits.…”

Fluorescence-Free Biosensor Methods in Detection of Food Pathogens with a Special Focus on Listeria monocytogenes

“…These are intrinsic problems in the conventional SPR methods. For the extension of SPR applications to food safety, either new surfaces [ 28 , 29 , 30 ] have been tested or new portable instruments have been developed [ 31 ].…”

Recent advancements in microfluidic chip biosensor detection of foodborne pathogenic bacteria: a review

“…The unlabeled characteristic of the device can ensure its reproducibility. At present, the device is being further miniaturized to facilitate POCT [ 103 ]. Demirci et al [ 32 ] prepared a portable, multichannel, and inexpensive microfluidic-integrated SPR platform which can quickly detect and quantify bacteria, namely E. coli and S. aureus .…”