Ultra-sensitive chemical and biological analysisviaspecialty fibers with built-in microstructured optofluidic channels

Abstract

All-in-fiber optofluidics is an analytical tool that provides enhanced sensing performance with simplified analyzing system design. Currently, its advance is limited either by complicated liquid manipulation and light injection configuration or by low sensitivity resulting from inadequate light-matter interaction. In this work, we design and fabricate a side-channel photonic crystal fiber (SC-PCF) and exploit its versatile sensing capabilities in in-line optofluidic configurations. The built-in microfluidic channel of the SC-PCF enables strong light-matter interaction and easy lateral access of liquid samples in these analytical systems. In addition, the sensing performance of the SC-PCF is demonstrated with methylene blue for absorptive molecular detection and with human cardiac troponin T protein by utilizing a Sagnac interferometry configuration for ultra-sensitive and specific biomolecular specimen detection. Owing to the features of great flexibility and compactness, high-sensitivity to the analyte variation, and efficient liquid manipulation/replacement, the demonstrated SC-PCF offers a generic solution to be adapted to various fiber-waveguide sensors to detect a wide range of analytes in real time, especially for applications from environmental monitoring to biological diagnosis.

Functionalized Microstructured Optical Fibers: Materials, Methods, Applications

“…Another example of the MOF-based optofluidic platform has shown that suspended-core MOFs functionalized with gold nanoparticles, can be utilized for real-time analyte monitoring through efficient RI sensing ( Figure 11) [67,68].…”

“…Another example of the MOF-based optofluidic platform has shown that suspended-core MOFs functionalized with gold nanoparticles, can be utilized for real-time analyte monitoring through efficient RI sensing ( Figure 11) [67,68]. The concept of low-cost microfluidic-compatible sensing platform for fast detection of small RI variations was realized with exposed-core optical fibers functionalized with plasmonic gold nanoparticles [69].…”

“…Table 1 summarizes the reviewed techniques applied for MOFs functionalization, their potential applications, and describes the used MOF types. In situ catalyst monitoring [66] Suspended-core Gold nanoparticles-functionalized suspended-core MOF Efficient RI sensing featuring the real-time analyte monitoring [67,68] Suspended-core and exposed-core Functionalization of hollow channels with a monoazacrown bearing spiropyran; attachment of the fluorophore to a polyelectrolyte-coated fiber's surface Biosensors for the reversible and low volume scale measurement of metal ions; real-time detection of zinc, aluminum, and lithium ions [70][71][72] Solid-core…”

Surface‐enhanced Raman scattering‐active photonic crystal fiber probe: Towards next generation liquid biopsy sensor with ultra high sensitivity

“…The photonic crystal and the air channel enable a tight control of the properties of the guided light such as single‐mode propagation, and an efficient liquid infiltration . SiC‐PCF is, therefore, very suitable for in‐line opto‐fluidic lab‐in‐fiber applications . It is nevertheless more complicated to fabricate than conventional SC‐PCF or SuC‐PCFs.…”

“…In addition, PCFs can also be integrated with microdevices for sensing applications. Recently, Zhang et al used a SiC‐PCF to build an in‐line optofluidic Sagnac interferometer in order to detect several analytes using refractive index sensing and as a proof of concept, they detected human cardiac troponin T. Unterkofler et al analyzed the photoaquation of cyanocobalamin (CNCbl) to aquacobalamin when a solution of CNCbl was exposed to laser excitation inside a HC‐PCF in an in‐house microfluidic circuitry. In another study Xiao et al used a HC‐PCF to fabricate all‐in‐fiber microcells.…”