U-Shaped and Surface Functionalized Polymer Optical Fiber Probe for Glucose Detection

In this work we show an optical fiber evanescent wave absorption probe for glucose detection in different physiological media. High selectivity is achieved by functionalizing the surface of an only-core poly(methyl methacrylate) (PMMA) polymer optical fiber with phenilboronic groups, and enhanced sensitivity by using a U-shaped geometry. Employing a supercontinuum light source and a high-resolution spectrometer, absorption measurements are performed in the broadband visible light spectrum. Experimental results suggest the feasibility of such a fiber probe as a low-cost and selective glucose detector.This work has been funded in part by the European Regional Development Fund; in part by the Ministerio de Economia y Competitividad under project TEC2015-638263-C03-1-R; and in part by the Gobierno Vasco/Eusko Jaurlaritza under projects IT933-16, IT718-13, and ELKARTEK (KK-2016/0030, KK-2017/00033, KK-2017/00089, KK-2016/0059). Authors are also grateful to the technical and human support provided by SGIKER (UPV/EHU, MICINN, GV/EJ, ERDF, and ESF). The work of Mikel Azkune was supported in part by a research fellowship from the Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Vicerrectorado de Euskera y Formacion Continua

Design and development of polymer optical fiber based platforms for glucose detection.

127 p.Tesi-lan honetan polimerozko zuntz optikoetan oinarritzen diren glukosa detekzioa egiteko bi plataformaaurkezten dira. Lehenik eta behin, tesiaren testuingurua deskribatzen da, horretarako biosentsoreen zeinpolimerozko zuntz optikoen oinarriak, garapen historikoa eta mugarri garrantzitsuenak azalduz. Ondoren,tesian zehar jorratzen diren detekzio tekniken azalpen teoriko bat egiten da, uhin ebaneszentea eta Ramanespektroskopia zer diren azalduz.Horren ostean, lehen detekzio plataforma azaltzen da, U formako nukleo hutsezko polimerozko zuntzoptikozko zunda bat erabiliz. Zunda honen gainazala fenilboroniko taldeekin funtzionalizatu eta AlizarinRed S izeneko koloratzailearekin kargatzen da. Honenbestez, zundaren ingurunean glukosa badago,glukosak koloratzailea desplazatu eta uhin ebaneszentearen xurgapenean aldaketak emango dira,glukosaren detekzioa gauzatuz. Honela, glukosa 0.1 mol/l-ko kontzentrazioan eta hainbat inguruneezberdinetan detektatu da.Hurrengo kapituluan, bigarren detekzio plataforma azaltzen da, zuntz bidez anplifikaturiko Ramanespektroskopian oinarritua. Kasu honetan, likidoz beteriko nukleodun polimerozko zuntz optikomikroegituratuak diseinatu, fabrikatu eta hiru zuntzen arteko konparaketa egiten da. Kasurik onenean, 5mmol/l-ko kontzentrazioan aurkitzen glukosaren zenbaketa limitea lortzen da ingurune urtsuan,erresoluzio nahikoa izanik SGLT2 inhibitore terapiaren jarraipena egiteko maila klinikoan.Azkenik, bi detekzio sistemak aplikazio errealetan erabiltzeko zein hobekuntza egin behar diren azaltzenda, esparru horietako lehen emaitza batzuk azalduz

Progress in Probe-Based Sensing Techniques for In Vivo Diagnosis

Advancements in robotic surgery help to improve the endoluminal diagnosis and treatment with minimally invasive or non-invasive intervention in a precise and safe manner. Miniaturized probe-based sensors can be used to obtain information about endoluminal anatomy, and they can be integrated with medical robots to augment the convenience of robotic operations. The tremendous benefit of having this physiological information during the intervention has led to the development of a variety of in vivo sensing technologies over the past decades. In this paper, we review the probe-based sensing techniques for the in vivo physical and biochemical sensing in China in recent years, especially on in vivo force sensing, temperature sensing, optical coherence tomography/photoacoustic/ultrasound imaging, chemical sensing, and biomarker sensing

Design and development of polymer optical fiber based platforms for glucose detection.

127 p.Tesi-lan honetan polimerozko zuntz optikoetan oinarritzen diren glukosa detekzioa egiteko bi plataformaaurkezten dira. Lehenik eta behin, tesiaren testuingurua deskribatzen da, horretarako biosentsoreen zeinpolimerozko zuntz optikoen oinarriak, garapen historikoa eta mugarri garrantzitsuenak azalduz. Ondoren,tesian zehar jorratzen diren detekzio tekniken azalpen teoriko bat egiten da, uhin ebaneszentea eta Ramanespektroskopia zer diren azalduz.Horren ostean, lehen detekzio plataforma azaltzen da, U formako nukleo hutsezko polimerozko zuntzoptikozko zunda bat erabiliz. Zunda honen gainazala fenilboroniko taldeekin funtzionalizatu eta AlizarinRed S izeneko koloratzailearekin kargatzen da. Honenbestez, zundaren ingurunean glukosa badago,glukosak koloratzailea desplazatu eta uhin ebaneszentearen xurgapenean aldaketak emango dira,glukosaren detekzioa gauzatuz. Honela, glukosa 0.1 mol/l-ko kontzentrazioan eta hainbat inguruneezberdinetan detektatu da.Hurrengo kapituluan, bigarren detekzio plataforma azaltzen da, zuntz bidez anplifikaturiko Ramanespektroskopian oinarritua. Kasu honetan, likidoz beteriko nukleodun polimerozko zuntz optikomikroegituratuak diseinatu, fabrikatu eta hiru zuntzen arteko konparaketa egiten da. Kasurik onenean, 5mmol/l-ko kontzentrazioan aurkitzen glukosaren zenbaketa limitea lortzen da ingurune urtsuan,erresoluzio nahikoa izanik SGLT2 inhibitore terapiaren jarraipena egiteko maila klinikoan.Azkenik, bi detekzio sistemak aplikazio errealetan erabiltzeko zein hobekuntza egin behar diren azaltzenda, esparru horietako lehen emaitza batzuk azalduz

Sensores em POF baseados em intensidade para a avaliação da qualidade de águas

Nowadays there is the need for low-cost and user-friendly solutions for water quality assessment which can allow for remote, in-site and real-time monitoring of water contaminants. POF sensing technologies combined with specially developed sensitive layers for chemical detection may offer these possibilities, with proper interrogation systems. POF sensing platforms based on low-cost procedures were developed and characterized using aqueous solutions of different refractive indices (RI). The POF RI sensors were optimized by varying the length and/or roughness of the sensing region. The suitability of these sensing platforms for chemical detection was evaluated through the coating with sensitive layers, namely molecularly imprinted polymers (MIPs) using different deposition techniques. The dependency of proteins immobilization on the POF’s surface was evaluated aiming future developments in chemical detection using POF biosensors. A D-shaped POF chemical sensor was successfully developed using a sensitive MIP layer, allowing the detection of perfluorooctanoate (POFA/PFO-) in aqueous media with a limit of detection of 0.20 – 0.28 ppb. The collaboration of researchers from different areas was essential for the success of the developed work.Hoje em dia há uma necessidade de soluções simples e de baixo custo para a avaliação da qualidade de águas e que permitam a monitorização remota de contaminantes, no local e em tempo real. As tecnologias baseadas em POF podem oferecer essa possibilidade através de sistemas de interrogação óptica adequados, combinados com camadas sensíveis especialmente desenvolvidas para detecção química. As plataformas ópticas baseadas em POF foram desenvolvidas e caracterizadas com soluções aquosas com diferentes índices de refracção. Os sensores foram optimizados através da variação do comprimento e/ou rugosidade da região sensível. A capacidade de detecção química das plataformas ópticas desenvolvidas foi avaliada através do revestimento com camadas sensíveis, nomeadamente polímeros molecularmente impressos (PMI), utilizando diferentes técnicas de deposição. A dependência da imobilização de proteínas na superfície de POFs modificadas foi avaliada com o objectivo de desenvolver biossensores para detecção química. Um sensor POF para detecção química, em configuração D-shape, foi desenvolvido com sucesso através do revestimento com um PMI, permitindo a detecção de perfluorooctanoato (POFA/PFO-) em soluções aquosas com um limite de detecção entre 0.20 – 0.28 ppb. A colaboração com investigadores de diferentes áreas foi essencial para o sucesso do trabalho desenvolvido.Programa Doutoral em Engenharia Físic

Surface-enhanced Raman spectroscopy in 3D electrospun nanofiber mats coated with gold nanorods

Nanofibers functionalized by metal nanostructures and particles are exploited as effective flexible substrates for SERS analysis. Their complex three-dimensional structure may provide Raman signals enhanced by orders of magnitude compared to untextured surfaces. Understanding the origin of such improved performances is therefore very important for pushing nanofiber-based analytical technologies to their upper limit. Here we report on polymer nanofiber mats which can be exploited as substrates for enhancing the Raman spectra of adsorbed probe molecules. The increased surface area and the scattering of light in the nanofibrous system are individually analyzed as mechanisms to enhance Raman scattering. The deposition of gold nanorods on the fibers further amplifies Raman signals due to SERS. This study suggests that Raman signals can be finely tuned in intensity and effectively enhanced in nanofiber mats and arrays by properly tailoring the architecture, composition, and light-scattering properties of the complex networks of filaments.Comment: 29 pages, 9 figures, 1 Tabl

Fluorescent nanoparticles for sensing

Nanoparticle-based fluorescent sensors have emerged as a competitive alternative to small molecule sensors, due to their excellent fluorescence-based sensing capabilities. The tailorability of design, architecture, and photophysical properties has attracted the attention of many research groups, resulting in numerous reports related to novel nanosensors applied in sensing a vast variety of biological analytes. Although semiconducting quantum dots have been the best-known representative of fluorescent nanoparticles for a long time, the increasing popularity of new classes of organic nanoparticle-based sensors, such as carbon dots and polymeric nanoparticles, is due to their biocompatibility, ease of synthesis, and biofunctionalization capabilities. For instance, fluorescent gold and silver nanoclusters have emerged as a less cytotoxic replacement for semiconducting quantum dot sensors. This chapter provides an overview of recent developments in nanoparticle-based sensors for chemical and biological sensing and includes a discussion on unique properties of nanoparticles of different composition, along with their basic mechanism of fluorescence, route of synthesis, and their advantages and limitations

Developments in nanoparticles for use in biosensors to assess food safety and quality

The following will provide an overview on how advances in nanoparticle technology have contributed towards developing biosensors to screen for safety and quality markers associated with foods. The novel properties of nanoparticles will be described and how such characteristics have been exploited in sensor design will be provided. All the biosensor formats were initially developed for the health care sector to meet the demand for point-of-care diagnostics. As a consequence, research has been directed towards miniaturization thereby reducing the sample volume to nanolitres. However, the needs of the food sector are very different which may ultimately limit commercial application of nanoparticle based nanosensors. © 2014 Elsevier Ltd

Label-free glucose biosensor based on enzymatic graphene oxide-functionalized tilted fiber grating

A label-free biosensor based on graphene oxide (GO) and glucose oxidase (GOD) functionalized tilted fiber grating (TFG) with large tilted angle is proposed for low concentration glucose detection. Taking advantages of sufficient binding sites of the GO with oxygen-containing groups, the enzymes (GOD) are covalently immobilized onto GO-deposited TFG via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxyl succinimide cross-liner. Surface characterizations with optical microscopy, scanning electron microscopy, Raman and infrared spectroscopy provide detailed assessments and evidences about the homogeneity of GO deposition and the effectiveness of enzyme modification. Through the specific catalysis reaction of GOD on the glucose, a considerable refractive index change in local microenvironment around the TFG results in the resonant wavelength shifts of cladding modes. The detection results of the low-concentration glucose demonstrate that the resonant wavelength has a linear response to the glucose concentration in the range of 0–8 mM with a response coefficient of ∼0.24 nm/mM, showing an enhanced sensitivity and bio-selectivity compared with the pristine TFG. The miniaturized size and remote label-free sensing capacity of the proposed device permit a multitude of opportunities for single-point measurement in harsh conditions and hard-to-reach spaces, presenting a promising candidate for label-free glucose detection for disease diagnosis, pharmaceutical research and bioengineering applications