Abstract
In this work, we analyze a remote optical sensor system composed of two Fiber Bragg Gratings (FBGs) and one Long Period Grading (LPG) capable of simultaneously sensing the temperature and the refractive index, separated by 50 km from the optical source and the interrogation unit. Since the active components of the system and the sensor head are separated over such a large distance, it is necessary to consider Raman amplification o strengthen the optical signal. We present both experimental measurements and the results of numerical simulations, which describe the signal evolution and predict the measurement results for a remote sensor based on a LPG. The simulation codes are also used to study a hybrid sensor composed of two FBGs with a LPG. We show that the power ratio between the two central wavelengths of the FBG has a linear relation with the change of refractive index of the sensored medium.

Abstract
A single-mode nonadiabatic tapered optical fiber (NATOF) sensor was inserted into a fiber loop mirror (FLM) enabling us to tune its sensitivity towards refractive index (RI). The NATOF was fabricated by the heat pulling method, utilizing a CO laser. The adjustment of the polarization controllers (PCs) inserted in loop allowed us to excite different cladding modes in the interferometric taper resulting in different optical paths for the clockwise and the counterclockwise beams. By variation of the PCs' settings, the sensitivity of the sensor for RI in the range from 1.3380 to 1.3510 could be tuned from 876.24 to 1233.07 nm/RIU. Experimental results show that the sensitivity to the external RI increased with the order of the cladding mode.

Abstract
Cyanobacteria deteriorate the water quality and are responsible for emerging outbreaks and epidemics causing harmful diseases in Humans and animals because of their toxins. Microcystin-LR (MCT) is one of the most relevant cyanotoxin, being the most widely studied hepatotoxin. For safety purposes, the World Health Organization recommends a maximum value of 1 mu g L(-1) of MCT in drinking water. Therefore, there is a great demand for remote and real-time sensing techniques to detect and quantify MCT. In this work a Fabry-Perot sensing probe based on an optical fibre tip coated with a MCT selective thin film is presented. The membranes were developed by imprinting MCT in a sol-gel matrix that was applied over the tip of the fibre by dip coating. The imprinting effect was obtained by curing the sol-gel membrane, prepared with (3-aminopropyl) trimethoxysilane (APTMS), diphenyl-dimethoxysilane (DPDMS), tetraethoxysilane (TEOS), in the presence of MCT. The imprinting effect was tested by preparing a similar membrane without template. In general, the fibre Fabry-Perot with a Molecular Imprinted Polymer (MIP) sensor showed low thermal effect, thus avoiding the need of temperature control in field applications. It presented a linear response to MCT concentration within 0.3-1.4 mu g L(-1) with a sensitivity of -12.4 +/- 0.7 nm L mu g(-1). The corresponding Non-Imprinted Polymer (NIP) displayed linear behaviour for the same MCT concentration range, but with much less sensitivity, of -5.9 +/- 0.2 nm L mu g(-1). The method shows excellent selectivity for MCT against other species co-existing with the analyte in environmental waters. It was successfully applied to the determination of MCT in contaminated samples. The main advantages of the proposed optical sensor include high sensitivity and specificity, low-cost, robustness, easy preparation and preservation.

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 enabled the production of fiber probes, by self-guiding photo-polymerization, with 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.

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.

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.