Chemically immobilized T4-bacteriophage for specific Escherichia coli detection using surface plasmon resonance

Abstract

A bioassay platform using T4 bacteriophage (T4) as the specific receptor and surface plasmon resonance (SPR) as the transduction technique has been developed for the detection of Escherichia coli K12 bacteria. The T4 phages have been covalently immobilized onto gold surfaces using a self-assembled monolayer of dithiobis(succinimidyl propionate) (DTSP). Substrates of BSA/EA-T4/DTSP/Au prepared using different T4 phage concentrations have been characterized using scanning electron microscopy (SEM). The studies reveal that the use of DTSP results in a uniform binding of T4 phages onto the surface. The SPR analysis demonstrates that these BSA/EA-T4/DTSP/Au interfaces can detect the E. coli K12 with high specificity against non-host E. coli NP10 and NP30. Results of SEM and SPR studies indicate that the maximum host bacterial capture is obtained when 1.5 × 10(11) pfu ml(-1) concentration of T4 phages was used for immobilization. The surface of these chemically anchored phage substrates can be regenerated for repeated detection of E. coli K12 and can be used for detection in 7 × 10(2) to 7 × 10(8) cfu ml(-1) range. The results of these studies have implications for the development of online bioassays for the detection of various food and water borne pathogens using the inherent selectivity of bacteriophage recognition.

The Detection of Agricultural Products and Food Using Terahertz Spectroscopy: A Review

“…Interestingly, they obtained a correlation between the fiber absorption losses and the bacteria concentration of the samples. The detection limit was around 10 4 cfu mL −1 , which was comparable with existing commercially available methods (84). This research presented a label-free method that allows not only detection of E. coli but also quantitative measurement of its concentration, without any fingerprint features of the target bacteria in the terahertz spectrum.…”

Terahertz spectroscopy for bacterial detection: opportunities and challenges

“…The fiber transmission decreased first due to the binding of bacteria; it then increased due to bacterial lysis, but was still lower than the level of the first step as a result of fragments remaining bound to the fiber surface. From the correlation between the fiber absorption losses and bacterial concentration, a detection limit of 10 4 cfu/ml was obtained, which is comparable to existing commercial methods (Arya et al 2011). Moreover, the sensitive detection of bacteria in both ambient and aqueous environments is feasible via THz metamaterials (Park et al 2014).…”

Pathogen detection using engineered bacteriophages

“…There are numerous proof-ofconcept-stage phage-based detectors in development that encompass a broad range of target pathogens (Table 4). All fall under the common detection schemes discussed above, with several now being preliminarily merged with transducer elements to create standalone electrical, piezoelectric, surface plasmon resonance, optical, and optoelectronic-based biosensors [83,[96][97][98][99][100]. However, with none yet undergoing robust real-world testing, their effectiveness and value in comparison with conventional PCR and ELISA detection strategies is difficult to gauge.…”