Integration of a 3D hydrogel matrix within a hollow core photonic crystal fibre for DNA probe immobilization

Abstract

Abstract. In this paper, we demonstrate the integration of a 3D hydrogel matrix within a hollow core Photonic Crystal Fibre (HC-PCF). In addition we also show the fluorescence of Cy5-labelled DNA molecules immobilised within the hydrogel formed in two different types of HC-PCF. The 3D hydrogel matrix is designed to bind with the amino-groups of biomolecules using an appropriate cross-linker, providing higher sensitivity and selectivity than the standard 2D coverage, enabling a greater number of probe molecules to be available per unit area. The HC-PCFs, on the other hand, can be designed to maximise the capture of fluorescence to improve sensitivity and provide longer interaction lengths.This could enable the development of fibre-based point-of-care and remote systems, where the enhanced sensitivity would relax the constraints placed on sources and detectors. In this paper, we will discuss the formation of such polyethylene glycol diacrylate (PEGDA) hydrogels within a HC-PCF, including their optical properties such as light-propagation and auto-fluorescence.

Hydrogel Based Biosensors for In Vitro Diagnostics of Biochemicals, Proteins, and Genes

“…However, there is a fundamental limitation of 2D surfaces that lower the sensitivity of detection systems when probe DNA is confined to the surface of substrates. It is likely that the efficiency and kinetics of hybridization are highly influenced by the surface density of DNA strands and their relative mobility . Unlike 2D surfaces, the hydrogel can provide an increased accessibility of gel‐immobilized nucleic acids for more rapid and efficient base‐pair hybridization .…”

Easy Daylight Fabricated Hydrogel Array for Colorimetric DNA Analysis

“…So, daylight as well as every common laboratory lamp (e.g., Daylight Slimline Magnifying Lamp) with light emission in the range of 405 nm can induce the polymerization process. Another method using visible light is realized by including Eosin Y as a reaction component . Since Eosin Y is a type II initiator, its chromophore persist after polymerization and hampers fluorescence measurements.…”

“…Another promising approach for a combined polymerization and in situ DNA crosslinking was introduced. Within this application, amino‐modified DNA participated in the polymerization process induced by exposure with UV light or laser light in the visible range . Also, thymin18‐DNA ensured stable binding to the hydrogel components under UV irradiation .…”

DNA probe detection within 3D hydrogel matrix in a hollow core photonic crystal fibre

“…In a HC-PCF 1060 6 with a core diameter of 9.8 μm, this is achieved by changing the refractive index to 1.33. Therefore, the first batch of HC-PCFs 1060 was silanised following a specific chemical protocol as described in 7 . Briefly, the internal surface of each fibre was covered with silane agents (solution of AMPTS 3%) and photo-initiator molecules (solution of 0.5 mM Eosin Y and 25 mM EDAC) resulting in fibre cross sections under white light illumination, as shown in Fig.…”

“…Such fibres are unique, due to the light guiding mechanism inside their structure 5 which enables to shift the guided frequencies by changing the refractive index within their holes 6 and improves the light interaction within sample. In a recent paper, we propose to combine the optical benefits of such fibres, especially the HC-PCF, and use them for molecule immobilisation, tagging, and measurement based on hydrogel 7 . Hydrogel is a competing technology which offers three dimensional matrix for the immobilisation of molecules and it is considered to offer higher sensitivity than two dimensional immobilisation, common to a surface coverage devices 8 for the detection and selection of attached biomolecules inside its structure.…”