A Double-Taper Optical Fiber-Based Radiation Wave Other than Evanescent Wave in All-Fiber Immunofluorescence Biosensor for Quantitative Detection of Escherichia coli O157:H7

Abstract

Cylindrical or taper-and-cylinder combination optical fiber probe based on evanescent wave has been widely used for immunofluorescence biosensor to detect various analytes. In this study, in contrast to the contradiction between penetration depth and analyte diameter of optical fiber probe-based evanescent wave, we demonstrate that double-taper optical fiber used in a radiation wave-based all-fiber immunofluorescence biosensor (RWAIB) can detect micron-scale analytes using Escherichia coli O157:H7 as representative target. Finite-difference time-domain method was used to compare the properties of evanescent wave and radiation wave (RW). Ray-tracing model was formulated to optimize the taper geometry of the probe. Based on a commercial multi-mode fiber, a double-taper probe was fabricated and connected with biosensor through a “ferrule connector” optical fiber connector. The RWAIB configuration was accomplished using commercial multi-mode fibers and fiber-based devices according to the “all-fiber” method. The standard sample tests revealed that the sensitivity of the proposed technique for E. coli O157:H7 detection was 103 cfu·mL−1. Quantitation could be achieved within the concentration range of 103 cfu·mL−1 to 107 cfu·mL−1. No non-specific recognition to ten kinds of food-borne pathogens was observed. The results demonstrated that based on the double-taper optical fiber RWAIB can be used for the quantitative detection of micron-scale targets, and RW sensing is an alternative for traditional evanescent wave sensing during the fabrication of fiber-optic biosensors.

A New Optical Fiber Probe-Based Quantum Dots Immunofluorescence Biosensors in the Detection of Staphylococcus aureus

“…The time response curve shows that the signal reached the maximum value instantly after the laser turning on and then decreased back gradually. This was caused by photo-bleaching (Liu et al, 2014;Zhang et al, 2014). After decreasing back, the fluorescence signal gradually tended to be stable.…”

“…A taper-and-cylinder combination optical fiber was prepared as the fiber probe. It was fabricated with a simple static tube etching method with 40% hydrofluoric acid (HF) as the etchant (Liu et al, 2014;Zhang et al, 2014). The fiber probe (inset in Figure 1A) consisted of a tapered section and a sensing region, whose length were approximately 0.03 and 1 cm, respectively.…”

“…We developed an optical fiber probe-based immunofluorescence biosensor that combined the advantages of antigen-antibody specificity, fluorescence labeling and transmission of fluorescence signals along the optical fiber. The surface of the probe of the biosensor was immobilized with Escherichia coli-specific antibodies, and the detection sensitivity for E. coli reached 10 3 CFU/ml (CFU, colony forming units, an estimate of viable bacterial numbers usually existing in the form of colony), with high specificity (Liu et al, 2014;Zhang et al, 2014). However, the common fluorescence labelling techniques applied in their biosensor still have disadvantages, such as short fluorescence lifetime and spectral overlap affecting detection accuracy (Pu and Liu, 2009).…”

Sensitive Leptospira DNA detection using tapered optical fiber sensor

“…Finally, glutaraldehyde as a bifunctional aldehyde is deposited onto the fiber surface to form an arm linker, which makes it possible for probe DNA to be covalently bonded with fiber surface [49]. This technique has been successfully demonstrated in several studies [50][51][52][53][54]. Figure 2 summarizes the process to functionalize the tapered optical fiber surface.…”

Fundamental mode intensity evolution in tapered optical fibres

“…Tapered fibres are enjoying renewed interest because of useful applications as optical fibre sensors and couplers [2]. Examples of these are evanescent wave biosensors [3][4][5][6], hydrogen detection [7], astro-photonics devices [8,9], fibre optic laser applications Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.…”