Multisensor probe for soil monitoring

Olmos, Ángel Delgado; Vargas-Sansalvador, Isabel M. Pérez de; Palma, A.; Banqueri, J.; Fernández-Ramos, M.D.; Capitán-Vallvey, L.F.

doi:10.1016/j.snb.2011.07.011

Cited by 9 publications

(4 citation statements)

References 13 publications

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“…As discussed above, the sensing luminophore containing the PtOEP complex can be excited at two different wavelengths in order to obtain an emission of light whose intensity depends on the surrounding oxygen concentration. In a previous work, a green LED with peak emission at 525 nm was used [21][22][23]. However in this case, a LED with emission in the UV band was selected since it causes only negligible direct and stray optical interference in the image acquired to predict the O 2 concentration.…”

Section: Instrument Calibrationmentioning

confidence: 99%

“…In previous works, the authors presented portable instrumentation for the determination of gaseous oxygen based on the quenching of luminophore PtOEP [21][22][23]. In this work we use CCD micro-cameras, both external and included in a smartphone, to evaluate the possibilities for oxygen sensing, and in general for chemical sensing, with highly distributed and available imaging devices.…”

Section: Introductionmentioning

confidence: 99%

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Determination of O2 using colour sensing from image processing with mobile devices

López-Ruiz

Martínez-Olmos

Vargas-Sansalvador

et al. 2012

Sensors and Actuators B: Chemical

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Section: Instrument Calibrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of O2 using colour sensing from image processing with mobile devices

López-Ruiz

Martínez-Olmos

Vargas-Sansalvador

et al. 2012

Sensors and Actuators B: Chemical

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“…The challenge now is to simplify the whole analysis system, avoiding the necessity for specialised training. Several studies can be found in the literature investigating alternatives to classic analytical methods, for instance, with the use of portable devices [2][3][4][5][6] or the novel usage of smartphones as detectors [7][8][9]. In this way, laboratory costs are reduced and there is no need for sample transportation.…”

Section: Introductionmentioning

confidence: 99%

Towards an autonomous microfluidic sensor for dissolved carbon dioxide determination

Sansalvador

López-Ruiz

Erenas

et al. 2018

Microchemical Journal

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In this work, we present a new system for the determination of dissolved carbon dioxide (from 7.2 ppm to 425.6ppm) in aqueous environments. Microfluidic technology has been incorporated in sensor design to reduce the volume of samples and reagents. Moreover, a detection system has been integrated in the chip, consisting of a white light-emitting diode as a light source and a high-resolution digital colour sensor as the detector, which are able to detect changes in colour produced by the reaction of the sensing chemistry and carbon dioxide in water.The optimised parameters found for the system are: flow rate 0.6 mL•min -1 , integration time 30 s and the time for pumping of solutions was 3 min, obtaining a LOD of 7.2 ppm. The CO2 response, reproducibility, precision, and stability of the sensing chemistry have been studied and compared with those obtained using benchtop instrumentation (i.e. a spectrophotometer), obtaining good agreement.

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“…19,20 In previous work, the authors presented portable instrumentation for the determination of gaseous oxygen based on the quenching of the well-known O 2 luminophore platinum octaethylporphyrin (PtOEP). 21,22 The use of photodiodes coated with a stabilized polystyrene membrane containing PtOEP makes it possible to sense O 2 using an analytical parameter similar to lifetime 23,24 and also the intensity of the luminescence in a stationary excitation state which is quantified by a color measurement. 25 Here, this luminophore is used to create a tag for smart packaging oriented to the monitoring of oxygen in a modified atmosphere.…”

mentioning

confidence: 99%

Screen Printed Flexible Radiofrequency Identification Tag for Oxygen Monitoring

et al. 2013

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In this work, a radiofrequency identification (RFID) tag with an optical indicator for the measurement of gaseous oxygen is described. It consists of an O2 sensing membrane of PtOEP together with a full electronic system for RFID communication, all printed on a flexible substrate. The membrane is excited by an LED at 385 nm wavelength and the intensity of the luminescence generated is registered by means of a digital color detector. The output data corresponding to the red coordinate of the RGB color space is directly related to the concentration of O2, and it is sent to a microcontroller. The RFID tag is designed and implemented by screen printing on a flexible substrate for the wireless transmission of the measurement to a remote reader. It can operate in both active and passive mode, obtaining the power supply from the electromagnetic waves of the RFID reader or from a small battery, respectively. This system has been fully characterized and calibrated including temperature drifts, showing a high-resolution performance that allows measurement of very low values of oxygen content. Therefore this system is perfectly suitable for its use in modified atmosphere packaging where the oxygen concentration is reduced below 2%. As the reading of the O2 concentration inside the envelope is carried out with an external RFID reader using wireless communication, there is no need for perforations for probes or wires, so the packaging remains completely closed. With the presented device, a limit of detection of 40 ppm and a resolution as low as 0.1 ppm of O2 can be reached with a low power consumption of 3.55 mA.

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Multisensor probe for soil monitoring

Cited by 9 publications

References 13 publications

Determination of O2 using colour sensing from image processing with mobile devices

Determination of O2 using colour sensing from image processing with mobile devices

Towards an autonomous microfluidic sensor for dissolved carbon dioxide determination

Screen Printed Flexible Radiofrequency Identification Tag for Oxygen Monitoring

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