Detection of bacteria using bacteriophages as recognition elements immobilized on long-period fiber gratings

Abstract

The paper presents for the first time a study of long-period gratings (LPGs) applied for label-free detection of specific bacteria using physically adsorbed bacteriophages. For the purposes of the experiment a number of highly sensitive LPGs working at the turning point of phase matching curve was fabricated in SMF28 fiber using UV exposure. We show that the device allows for real-time monitoring of phenomena taking place on the sensor's surface, including phage-bacteria interactions. For the applied conditions a resonance wavelength shift of ~1.3 nm induced by bacteria binding was observed.

Biosensing with optical fiber gratings

“…Finally, a series of other BREs, based on biointeractions such as enzymatic processes [58,59], biotin/streptavidin affinity [18,33,[60][61][62], virus-specific recognition (bacteriophage T4/Escherichia coli bacteria) [63][64][65][66] and biomimetic affinity processes with molecularly imprinted polymers (MIPs) [67], have been implemented (Table 3). …”

“…In the challenging field of bacteria detection, E. coli in particular, OFGs have been extensively used combined to bacteriophage T4 [63][64][65][66]: phages are organisms recognizing their host by specific receptor molecules on their surface, with high sensitivity and specificity to the bacteria and good thermal stability [81]. For all these reasons and being nontoxic to humans, as well as cheap and fast to produce, they emerged as a possible alternative to antibodies in biosensor development.…”

“…For all these reasons and being nontoxic to humans, as well as cheap and fast to produce, they emerged as a possible alternative to antibodies in biosensor development. In particular, they have been used, adsorbed, or covalently linked on silanes, as receptors for E. coli detection with LPGs and TAP-LPGs, achieving a LOD of 10 3 cfu ml −1 [63][64][65]. In addition, with a particular configuration of LPGs, constituted by two concatenated LPGs one of which serving for temperature compensation, different concentrations, down to 10 2 cfu ml −1 of E. coli, could be detected in water over the wide temperature range of 24°-40°C [66].…”

Next-Generation Antimicrobial Susceptibility Testing

“…The bacteriophage-based strategy has been successfully adapted for testing of M. tuberculosis (42), with optimization achieved by including recombinant phages containing luciferase genes (43). It was shown that the luciferase assay could be performed at low cost in 2 days (44) and could be applied successfully in laboratories in developing countries (45). Unfortunately, this innovative approach has not been broadly accepted in diagnostic microbiology laboratories, probably due to contamination (46) or phage resistance issues.…”

Long Period Gratings in New Generation Optical Fibers

“…Wang et al, 2009;Topliss et al, 2010). It should be noted that the number of biosensing applications with LPGs is rapidly growing and it can be foreseen www.intechopen.com that it will represent an area of major interest in coming years (Eggen et al, 2010;Smietana et al, 2011). In this context LPGs realized in Photonic Crystal Fibers are extremely attractive for the possibility to achieve very intense light matter interactions with a unique optofluidic design and with nano-liter sample consumption (Rindorf et al,2006;He et al, 2011).…”