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- Filippini, Daniel, 1968-, et al.
(författare)
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Sorting of apricots with computer screen photoassisted spectral reflectance analysis and electronic nose
- 2006
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 119:1, s. 70-77
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Tidskriftsartikel (refereegranskat)abstract
- Optical properties and aroma have been indicated as sources of information for the analysis of quality of fruits. Optical properties can be measured with several experimental arrangements and equipments that are often complex with result difficult to interpret. In recent years, a number of suggestions arose in the sensor community proposing the use of conventional computer peripheral devices as analytical instruments. Among them the combination of a computer screen and a webcam was demonstrated to be suitable to measure optical properties of materials. In this paper this arrangement is utilized to characterize the reflectance of apricot fruits that underwent different post-harvest treatment and mechanical damages. Optical measurements were complemented by aroma analysis with an electronic nose. The response of fruits to treatments was also monitored measuring CO2 (indicator of respiration) and ethylene (indicator of ripening), both these parameters are known to be influenced by post-harvest treatment and mechanical damages. Results show that a computer screen-webcam combination and an electronic nose are both sensitive to mechanical damages of fruits devising their use, after due optimization, for routine fruit sorting. © 2005.
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- Paolesse, R., et al.
(författare)
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Insights on the chemistry of a,c-biladienes from a CSPT investigation
- 2008
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 32:7, s. 1162-1166
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Tidskriftsartikel (refereegranskat)abstract
- Computer Screen Photoassisted Technique (CSPT) is a recent interesting approach for the development of optical sensor platforms using ubiquitous devices. We demonstrate here that the information obtained by CSPT measurements can be useful for other than sensing purposes and a computer set and a web camera can also be exploited as spectroscopic technique for the characterization of the compounds used as indicators. CSPT measurement data have been used to characterize novel features of the a,c-biladiene chemistry, which have been later confirmed by photophysical characterization carried out using classical instrumentation. The demonstrated analytical capabilities of a regular computer-web camera set reach a degree of complexity approaching that of fluorescence excitation-emission spectroscopy, something remarkable considering the exploitation of familiar and already well distributed devices. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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- Andersson, Mike, et al.
(författare)
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Development of a ChemFET sensor with molecular films of porphyrins as sensitive layer
- 2001
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Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 77:1-2, s. 567-571
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of chemical species with molecular films of porphyrins causes variations of the work function of the film itself, as it has been recently demonstrated by using the Kelvin probe technique. This characteristic makes porphyrins films suitable to be used as sensitive layers in ChemFET sensors. In this paper, we present a preliminary report about the fabrication and testing of such gas sensitive devices. The technological solutions towards an optimised device are also illustrated and discussed. © 2001 Elsevier Science B.V.
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- Di, Natale C., et al.
(författare)
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An experimental biomimetic platform for artificial olfaction
- 2008
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:9
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Tidskriftsartikel (refereegranskat)abstract
- Artificial olfactory systems have been studied for the last two decades mainly from the point of view of the features of olfactory neuron receptor fields. Other fundamental olfaction properties have only been episodically considered in artificial systems. As a result, current artificial olfactory systems are mostly intended as instruments and are of poor benefit for biologists who may need tools to model and test olfactory models. Herewith, we show how a simple experimental approach can be used to account for several phenomena observed in olfaction. An artificial epithelium is formed as a disordered distributed layer of broadly selective color indicators dispersed in a transparent polymer layer. The whole epithelium is probed with colored light, imaged with a digital camera and the olfactory response upon exposure to an odor is the change of the multispectral image. The pixels are treated as olfactory receptor neurons, whose optical properties are used to build a convergence classifier into a number of mathematically defined artificial glomeruli. A non-homogenous exposure of the test structure to the odours gives rise to a time and spatial dependence of the response of the different glomeruli strikingly similar to patterns observed in the olfactory bulb. The model seems to mimick both the formation of glomeruli, the zonal nature of olfactory epithelium, and the spatio-temporal signal patterns at the glomeruli level. This platform is able to provide a readily available test vehicle for chemists developing optical indicators for chemical sensing purposes and for biologists to test models of olfactory system organization. © 2008 Di Natale et al.
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- Di Natale, C, et al.
(författare)
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An artificial olfaction system based on the optical imaging of a large array of chemical reporters
- 2009
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Ingår i: SENSORS AND ACTUATORS B-CHEMICAL. - : Elsevier BV. - 0925-4005. ; 142:2, s. 412-417
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Tidskriftsartikel (refereegranskat)abstract
- Electronic noses are object of research since more than two decades; nonetheless. the analogies between natural and olfaction systems are still limited to the selectivity properties of the receptors. The implementation of more sophisticated features such as the large number of receptors and the glomeruli layer have been hampered by technical difficulties related to the management of a large number of contemporaneous signals. As demonstrated in the past, optical imaging is a read-out technique for sensors development that can provide large sensor arrays. In this paper an artificial olfaction system based on the imaging of a continuous layer of chemical indicators is illustrated. The system incorporates an array of thousands of sensors, corresponding to the pixels of the image. The choice of Computer Screen Photoassisted Technology as a platform for optical interrogation of the sensing layer allows for the definition of a strategy for an automatic definition of a glomeruli layer based on the classification of the optical fingerprints of the image pixels. Chemical indicators were dissolved into a polymeric matrix providing the further property of odor diffusion mimicking the functions of the olfactory mucosa. The system has been tested in a simple experiment and data have been treated applying a lateral inhibition to the glomeruli layer resulting in a dynamic pattern resembling that observed in natural olfaction.
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- Gatto, E., et al.
(författare)
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Polychromatic fingerprinting of excitation emission matrices
- 2008
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 14:20, s. 6057-6060
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Tidskriftsartikel (refereegranskat)abstract
- The ability of a ubiquitous polychromatic excitation to support the fingerprinting of the Excitation Emission Matrices (EEM) of fluorescent indicators was reported. Solutions of fluorescent molecules, with concentration of 2µM for the absorption and 10µM for the emission measurements were prepared. Spectroscopic grade THF and distilled water passed through Milli-Q purification system were used as solvents. EEM measurements were carried out on a spectrofluorimeter, operating in the 390-700 nm detection range, with excitations at 20 nm intervals within the same range. During the measurement, the screen displayed a sequence of 50 colors and for every color, the transmission and emission spectrum of both the reference and the sample were recorded. Illuminating colors in the red region are not able to excite fluorescence and this can be seen in the spectra for red light.
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