Light-directed functionalization methods for high-resolution optical fiber based biosensors

2015-01-01
Kahyaoğlu, Leyla Nesrin
Stensberg, Matthew
Rickus, Jenna L.
Recent advances in miniaturization and analyte-sensitive fluorescent indicators make optical fiber biosensors promising alternatives to microelectrodes. Optical sensing offers several advantages over electrochemical methods including increased stability and better spatial control to monitor physiological processes at cellular resolutions. The distal end of an optical fiber can be functionalized with different fluorophore/polymer combinations through mechanical, dip-coating or photopolymerization techniques. Unlike mechanical and dip-coating schemes, photopolymerization can spatially confine the sensing layer in the vicinity of light in a more reproducible and controllable manner. The objective of this study was to fabricate microscale fluorescence lifetime based optrodes using UV-induced photopolymerization. Six commercially available acrylate based monomers were investigated for stable entrapment of the oxygen sensitive porphyrin dye (PtTFPP) dye via photopolymerization at the end of optical fibers. Of these, the acrylate-functionalized alkoxysilane monomer, 3-methacryloxypropyl-trimethoxysilane (tradename Dynasylan MEMO) showed maximal response to changes in oxygen concentration. Dye-doped polymer microtips were grown at the ends 50 mu m optical fibers and sensitivity and response time were optimized by varying both the concentration of doped dye and the excitation power used for polymerization. The resulting sensors showed linear response within the physiologically relevant range of oxygen concentrations and fast response times. While applied here to oxygen sensing, the photopolymer formulation and process parameters described are compatible with a wide range of available organic dyes and can be used to pattern arrays of spots, needles or more complex shapes at high spatial resolution.

Suggestions

Optical light management by self-arrangement of inverted tetragonal pyramids on the silicon surface through copper-assisted etching technique in a single step
Donercark, Ergi; Çolakoğlu, Tahir; Terlemezoğlu, Makbule; Abak, Musa Kurtulus; Çiftpınar, Emine Hande; Bek, Alpan; Turan, Razit (2022-09-01)
Developing efficient light trapping techniques plays a crucial role in improving silicon (Si) solar cell parameters by decreasing optical losses. Herein, four various surface morphologies by copper-assisted chemical etching (Cu-ACE) technique under various process conditions were developed. The etching solution is composed of copper nitrate trihydrate (Cu[NO3](2)), hydrofluoric acid, and hydrogen peroxide in deionized water. The systematic correlation study on the molarity of the chemical ingredients reveal...
A modular micromachined high-density connector system for biomedical applications
Akın, Tayfun; Nikles, SA; Najafi, K (1999-04-01)
This paper presents a high-density, modular, low-profile, small, and removable connector system developed using micromachining technologies for biomedical applications. This system consists of a silicon or polyimide electrode with one end in contact with the biological tissue and its back-end supported in a titanium base (12.5 mm in diameter and 2.5 mm in height) that is fixed on the test subject. An external glass substrate (6 x 6 x 0.75 mm(3)), which supports a flexible polyimide diaphragm and CMOS buffer...
Slow light structure with enhanced delay-bandwidth product
Ustun, Kadir; KURT, HAMZA (2012-09-01)
In this study, we propose a special type of slow light photonic crystal (PC) waveguide structure to achieve slow light with an improved delay and bandwidth product (DBP). The waveguide is based on a triangular lattice PC with a line defect imposed by changing the radii and locations of the holes lying along the waveguide centerline. By altering the locations of these central holes, group indices ranging approximately from 25 to 40 are obtained over frequency intervals, attaining a nearly constant group inde...
Vibration-based Damage Identification in Sandwich Beams using Artificial Neural Networks
Şahin, Melin (2010-09-17)
This study investigates the effectiveness of the combination of global (natural frequency) and local (curvature mode shape) vibration characteristics of a glass fibre reinforced plastic sandwich beam-like structure when introduced to artificial neural networks for severity and location prediction of various damage with different extent at different locations. A finite element modelling and analysis tool is used to obtain the dynamic characteristics of both intact and damaged cantilever sandwich structures a...
Wideband long wave infrared metamaterial absorbers based on silicon nitride
ÜSTÜN, Kadir; Sayan, Gönül (2016-11-28)
In this paper, we present silicon nitride metamaterial absorber designs that accomplish large bandwidth and high absorption in the long wave infrared (LWIR) region. These designs are based on the metal-insulator-metal topology, insulator (silicon nitride), and the top metal (aluminum) layers are optimized to obtain high absorptance values in large bandwidths, for three different silicon nitride based absorber structures. The absorption spectrum of the final design reaches absorptance values above 90% in the...
Citation Formats
L. N. Kahyaoğlu, M. Stensberg, and J. L. Rickus, “Light-directed functionalization methods for high-resolution optical fiber based biosensors,” 2015, vol. 9486, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38030.