Highly sensitive biosensor based on UV-imprinted layered polymeric–inorganic composite waveguides

Abstract

An evanescent field sensor utilizing layered polymeric-inorganic composite waveguide configuration was developed in this work. The composite waveguide structure consists of a UV-imprint patterned polymer inverted rib waveguide with a Ta2O5 thin film sputter-deposited on top of the low refractive index polymer layers. The results suggest that the polymer based sensor can achieve a detection limit of 3 × 10(-7) RIU for refractive index sensing and corresponding limit of about 100 fg/mm2 for molecular adsorption detection. Besides enhancing the sensitivity significantly, the inorganic coating on the polymer layer was found to block water absorption effectively into the waveguide resulting in a stabilized sensor operation. The ability to use the developed sensor in specific molecular detection was confirmed by investigating antibody - antigen binding reactions. The results of this work demonstrate that high performance sensing capability can be obtained with the developed composite waveguide sensor.

Human IgG detection in serum on polymer based Mach-Zehnder interferometric biosensors

“…Additionally, according to the theory of evanescent sensing, inorganic sensors exhibit a higher sensitivity than polymer based sensors due to the higher achievable refractive index contrast of the waveguide layer to the surrounding medium . Nevertheless, because of the prospect of lower production costs, the development of all‐polymer based photonic sensing devices has been attracting increasing interest . So far, only a few examples for molecular sensing can be found in literature and these are limited to buffer solutions .…”

“…For their fabrication, conductive polymers for electrochemical sensors (e.g. tosylate doped poly(3,4‐ethylenedioxythiophene, PEDOT)) , cellulose for paper based sensors , or high refractive index polymers such as OrmoCore (Microresist Technology GmbH, Germany) and polyimide for photonic sensors have been investigated. Critical factors for polymer based sensors are the stability, non‐specific binding and sensitivity in real samples such as blood or serum .…”

Fluorescent polymer coated capillaries as optofluidic refractometric sensors

“…Here the polymer poly(benzyl methacrylate) (PB z MA, PolySciences) was used since it has a refractive index (1.568) significantly higher than that of silica (Δn ≈ 0.118) and otherwise similar properties to the more common poly(methyl methacrylate) (PMMA) often used in optical devices [26,27] including cylindrical microlasers [28]. It was also anticipated that PB z MA could be readily doped with laser dyes as for PMMA [28,29], and is demonstrated here.…”

Drift compensation using a multichannel slot waveguide Young interferometer

“…With the ridge waveguide geometry, 5.4% of the optical field intensity is confined into the surrounding water. Light-sample interaction can be further enhanced by applying a high index coating, such as TaO 5 , on the waveguide moving the mode outwards and increasing the confinement of the optical field intensity in the overlying medium [12,13]. The difference in the change of the effective RIs enables a YI sensor chip layout where all the waveguides are exposed to sample solutions similarly.…”