Environmental monitoring using a conventional photographic digital camera for multianalyte disposable optical sensors.

The primary interest of this study concerns the use of an inexpensive photographic digital camera as the detection system, using its own flash as the source of light to present a new analytical procedure to measure disposable multianalyte optical sensors for potassium, magnesium, hardness and conventional pH test strips. The camera arrangement was designed in a fixed position over an optical board with controllable ambient conditions. After acquiring the digital image, the analytical information contained in each test zone is analyzed using theRGB colour space. Reflectance measurements were developed to study the colourimetric and spectral characteristics of the test zones. We obtained the following application ranges and precision in terms of relative standard deviation (RSD %): for potassium from 3.2×10(-7) to 0.1 M with a precision between 3.3 and 4.0%, for magnesium from 2.7×10(-6) to 1.5 M showing a precision between 4.7 and 7.8% and finally for hardness from 4.3×10(-2) to 200,000 mg L(-1) CaCO(3) and between 5.1 and 7.0%. Moreover, the analytical characteristics of several optical procedures were compared with the results presented here. The proposed method was statistically validated against a reference procedure using samples of water from different sources and beverages, indicating that there are no significant statistical differences at a 95% confidence level.

[1]  Luis Fermín Capitán-Vallvey,et al.  Scanometric potassium determination with ionophore-based disposable sensors , 2008 .

[2]  L. Capitán-Vallvey,et al.  Magnesium-selective test strip. , 2005, Talanta.

[3]  G. Whitesides,et al.  Simple telemedicine for developing regions: camera phones and paper-based microfluidic devices for real-time, off-site diagnosis. , 2008, Analytical chemistry.

[4]  L. Capitán-Vallvey,et al.  Multianalyte imaging in one-shot format sensors for natural waters. , 2009, Analytica chimica acta.

[5]  Ernö Pretsch,et al.  Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 1. General Characteristics. , 1997, Chemical reviews.

[6]  Ulrich Henne,et al.  Read-Out of Multiple Optical Chemical Sensors by Means of Digital Color Cameras , 2009 .

[7]  D Filippini,et al.  Measurement strategy and instrumental performance of a computer screen photo-assisted technique for the evaluation of a multi-parameter colorimetric test strip. , 2006, The Analyst.

[8]  Kit L. Yam,et al.  A simple digital imaging method for measuring and analyzing color of food surfaces , 2004 .

[9]  Kenneth S Suslick,et al.  A colorimetric sensor array for organics in water. , 2005, Journal of the American Chemical Society.

[10]  Vladimir V. Apyari,et al.  Using a digital camera and computer data processing for the determination of organic substances with diazotized polyurethane foams , 2008 .

[11]  Jenny Gabrielson,et al.  Evaluation of redox indicators and the use of digital scanners and spectrophotometer for quantification of microbial growth in microplates. , 2002, Journal of microbiological methods.

[12]  Meinhard Knoll,et al.  Multisensor array for pH, K+, Na+ and Ca2+ measurements based on coated-film electrodes , 1992 .

[13]  Christos Mastichiadis,et al.  Simultaneous determination of pesticides using a four-band disposable optical capillary immunosensor. , 2002, Analytical chemistry.

[14]  Yoshio Suzuki,et al.  Optical Sensors for Ions and Protein Based on Digital Color Analysis , 2005 .

[15]  Kenneth S Suslick,et al.  Colorimetric sensor arrays for volatile organic compounds. , 2006, Analytical chemistry.

[16]  G. Whitesides,et al.  Three-dimensional microfluidic devices fabricated in layered paper and tape , 2008, Proceedings of the National Academy of Sciences.

[17]  Luis Fermín Capitán-Vallvey,et al.  Characterisation of a transparent optical test strip for quantification of water hardness , 2003 .

[18]  L. Capitán-Vallvey,et al.  Establishment of wide-range linear response curves in bulk optode sensors for cations based on ion exchange , 2006 .

[19]  Daniel Citterio,et al.  Lonophore-based lithium ion film optode realizing multiple color variations utilizing digital color analysis. , 2002, Analytical chemistry.

[20]  Audrey K. Ellerbee,et al.  Quantifying colorimetric assays in paper-based microfluidic devices by measuring the transmission of light through paper. , 2009, Analytical chemistry.

[21]  Mohsen Kompany-Zareh,et al.  SIMPLE METHOD FOR COLORIMETRIC SPOT-TEST QUANTITATIVE ANALYSIS OF FE(III) USING A COMPUTER CONTROLLED HAND-SCANNER , 2002 .

[22]  Martin Link,et al.  Photographing oxygen distribution. , 2010, Angewandte Chemie.

[23]  M. Badertscher,et al.  Neutral-carrier-based magnesium-selective electrode , 1988 .

[24]  Kurt Seiler,et al.  Design of a novel calcium-selective optode membrane based on neutral ionophores , 1990 .

[25]  Brian D. MacCraith,et al.  Multi-analyte optical chemical sensor employing a plastic substrate , 2000 .

[26]  H. Hisamoto,et al.  Visual and colorimetric lithium ion sensing based on digital color analysis. , 2000, Analytical chemistry.

[27]  Neal A. Rakow,et al.  A colorimetric sensor array for odour visualization , 2000, Nature.

[28]  Ursula E. Spichiger-Keller,et al.  Chemical Sensors and Biosensors for Medical and Biological Applications , 1998 .

[29]  Mário César Ugulino Araújo,et al.  Digital image-based titrations. , 2006, Analytica chimica acta.

[30]  A. Lapresta-Fernández,et al.  A simplified measurement procedure and portable electronic photometer for disposable sensors based on ionophore-chromoionophore chemistry for potassium determination , 2006, Analytical and bioanalytical chemistry.

[31]  Luis Fermín Capitán-Vallvey,et al.  Multi-ion detection by one-shot optical sensors using a colour digital photographic camera. , 2011, The Analyst.

[32]  D. Siswanta,et al.  Design and synthesis of calcium and magnesium ionophores based on double-armed diazacrown ether compounds and their application to an ion-sensing component for an ion-selective electrode , 1995 .

[33]  Luis Fermín Capitán-Vallvey,et al.  A disposable single-use optical sensor for potassium determination based on neutral ionophore , 2003 .

[34]  K. Tohda,et al.  Micro-miniature Autonomous Optical Sensor Array for Monitoring Ions and Metabolites 1: Design, Fabrication, and Data Analysis , 2006, Analytical sciences : the international journal of the Japan Society for Analytical Chemistry.

[35]  A. Egorov,et al.  Simultaneous determination of several pesticides with chemiluminescent immunoassay on a multi‐spot membrane strip , 1998 .

[36]  D. Citterio,et al.  Inkjet-printed microfluidic multianalyte chemical sensing paper. , 2008, Analytical chemistry.

[37]  Christophe A. Marquette,et al.  Screen-printed electrode microarray for electrochemiluminescent measurements , 2005 .

[38]  Agnès Bégué,et al.  Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test , 2008, Sensors.