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Publicações

Publicações por Pedro Jorge

2011

Yeast metabolic state identification using micro-fiber optics spectroscopy

Autores
Silva, JS; Castro, CC; Vicente, AA; Tafulo, P; Jorge, PAS; Martins, RC;

Publicação
INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
Saccharomyces cerevisiae morphology is known to be dependent on the cell physiological state and environmental conditions. On their environment, wild yeasts tend to form complex colonies architectures, such as stress response and pseudohyphal filaments morphologies, far away from the ones found inside bioreactors, where the regular cell cycle is observed under controlled conditions (e.g. budding and flocculating colonies). In this work we explore the feasibility of using micro-fiber optics spectroscopy to classify Saccharomyces cerevisiae S288C colony structures in YPD media, under different growth conditions, such as: i) no alcohol; ii) 1 % (v/v) Ethanol; iii) 1 % (v/v) 1-butanol; iv) 1 % (v/v) Isopropanol; v) 1 % (v/v) Tert-Amyl alcohol (2 Methyl-2-butanol); vi) 0,2 % (v/v) 2-Furadehyde; vii) 5 % (w/v) 5 (Hydroxymethyl)-furfural; and viii) 1 % (w/v) (-)-Adenosine3', 5'cyclic monophosphate. The microscopy system includes a hyperspectral camera apparatus and a micro fiber (sustained by micro manipulator) optics system for spectroscopy. Results show that micro fiber optics system spectroscopy has the potential for yeasts metabolic state identification once the spectral signatures of colonies differs from each others. This technique associated with other physico-chemical information can benefit the creation of an information system capable of providing extremely detailed information about yeast metabolic state that will aid both scientists and engineers to study and develop new biotechnological products.

2011

Towards single cell spectroscopy and refractometry in microfluidic chip platforms

Autores
Tillak, JB; Bernacka Wojcik, I; Barata, D; Jorge, PAS; Aguas, H; Oliva, AG;

Publicação
INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
This paper evaluates various strategies proposed for single cell refractometry and spectroscopy using fiber optic sensors and microfluidic chips. Details concerning design, fabrication and characterization of the chips will be addressed. Preliminary results obtained with alternative on-chip configurations using combination of fiber Bragg gratings with mirrored single mode and multimode fibers will be presented indicating the possibility of performing simultaneous assessment of cellular refractive index and absorption properties.

2010

Intrinsic Fabry-Perot cavity sensor based on chemical etching of a multimode graded index fiber spliced to a single mode fiber

Autores
Tafulo, PAR; Frazao, O; Jorge, PAS; Araujo, FM;

Publicação
FOURTH EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS

Abstract
An intrinsic Fabry-Perot cavity for high temperature and strain measurement is presented. The in-fibre cavity is formed by a chemical etched graded index optical fiber spliced to a single mode fiber. The intrinsic sensor obtained shows high sensitivity to strain (6.2 pm/mu epsilon) and rather low sensitivity to temperature (0.9 pm/degrees C), being suitable for applications as a strain gauge at high temperature.

2011

Controlling the sensitivity of a Non-adiabatic tapered optical fiber for measuring the refractive index using all fiber Sagnac loop Interferometer

Autores
Zibaii, MI; Jorge, PAS; Frazao, O; Latifi, H;

Publicação
INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
A single-mode non-adiabatic tapered optical fiber (NATOF) sensor was inserted into a Sagnac loop interferometer allowing tuning its sensitivity to refractive index (RI) by use of polarization control. By adjusting any polarization controllers inserted in the Sagnac loop interferometer, various cladding modes are selectively excited in each arm of the interferometric taper resulting into different phase changes for the clockwise and counterclockwise beams. By this method, sensitivity of the sensor for RI in the range from 1.3380 to 1.3510 was tuned between 876.24 RIU/nm to 1233.07 RIU/nm.

2010

Fabrication of dual analyte luminescent optrodes by photopolymerization

Autores
Jorge, PAS; Maule, C; Soppera, O; Marques, PVS;

Publicação
FOURTH EUROPEAN WORKSHOP ON OPTICAL FIBRE SENSORS

Abstract
A technique for the fabrication of luminescence based fiber optic optrodes with multiple analyte sensitivity is proposed. Combination of photosensitive polymers doped with different luminescent indicators was used to produce fiber probes, by self-guiding photopolymerization, having different geometries and sensing capabilities. Results demonstrating the method flexibility are shown with luminescent probes doped with CdSe/ZnS quantum dots and an organometalic ruthenium complex for simultaneous detection of oxygen and temperature.

2010

Fiber optic refractometric configurations for environmental sensing

Autores
Jorge, PAS;

Publicação
Advances in Sensors, Signals and Materials - 3rd WSEAS International Conference on Sensors and Signals, SENSIG'10, 3rd WSEAS International Conference on Materials Science, MATERIALS'10

Abstract
The implementation of refractometric based fiber optic sensors for environmental monitoring is discussed. Several sensing head configurations and interrogation schemes are presented and compared in the framework of different biochemical sensing applications. Results are presented demonstrating the suitability of this technology to monitor a diversity of chemical and biological parameters of environmental significance.

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