Evaluation of Digital Image Capture Devices for Colorimetric Detection on Printed Microzones

Souza, Fabrício R. de; Duarte-Junior, Gerson F.; Garcia, Paulo de Tarso; Coltro, Wendell K. T.

doi:10.5935/0100-4042.20140189

Cited by 8 publications

(12 citation statements)

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“…PADs have been used for different applications in association with electrochemical 20, 21 , mass spectrometry 22,23 and colorimetric detection 8,24 . The latter is one of the most popular detectors on PADs due to its global affordability and capability of capturing digital images with benchtop and handheld electronic devices 6,25,26 . Furthermore, the portability of electronic devices like cell phone camera, webcam, digital cameras, or handheld scanners allows their use for on-site applications.…”

Section: Introductionmentioning

confidence: 99%

“…The latter is one of the most popular detectors on PADs due to its global affordability and capability of capturing digital images with benchtop and handheld electronic devices 6,25,26 . Besides the advantages mentioned above, scanner allows auto-focus control and minimizes external interferences related to the light 25,27 . Among all portable electronic devices, scanner has been the most widely used to provide colorimetric measurements.…”

Section: Introductionmentioning

confidence: 99%

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Colorimetric determination of nitrite in clinical, food and environmental samples using microfluidic devices stamped in paper platforms

2015

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This study reports the use of microfluidic paper-based analytical devices (µPADs) associat e d with colorimetric detection for the determination of nitrite in clinical, food and environment a l samples. µPADs were fabricat ed by simple and fast stamping process in a geomet ry containin g eight circular detection zones and one central zone to sample inlet interconnected by microfluid i c channels . The colorimet ric determination of nitrite was performed through the modified Gries s reaction. Detection zones were spotted with a 0.75 µL aliquot of a solution containing 50 mmol L -1 sulfanilamide, 1.2 mol L -1 hydrochloric acid and 4 mmol L -1 N-(1-napthyl)ethy lenediamin e . The monitoring of the background colorimetric response revealed good stability over 12h for devices stored in the absence of light. After the addition of standard or real samples, the result in g images were captured with a scanner, converted to a color scale and analyzed in the magen t a channel. The analytical sensitivity and the limit of detection achieved after a preconcentrat io n stage were 0.56 (AU/µM ) and 5.6 µM , respectively. The preconcentrat ion provided an enrichment factor of ca. 3.2 times. The concentration levels of nitrite were successful ly determined in saliva, preservative water, ham, sausage and river water samples. The concentrat ion levels attained for each sample using µPADs were compared to the values found by spectrophotomet ry and there was no significative difference from one another at a confiden c e level of 95%.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Colorimetric determination of nitrite in clinical, food and environmental samples using microfluidic devices stamped in paper platforms

2015

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“…Recently, micro-uidic paper-based analytical devices (mPAD) have been demonstrated as a low-cost alternative to glass and polymer substrates for fabrication. 25,26 Patterning paper with hydrophobic barriers allows connement of liquid to well-dened hydrophilic regions, and uid ow via capillary action. 27 Paper is an attractive choice for developing microuidic devices because of widely available matrices made-up of extremely cheap cellulosic material, good compatibility with chemicals/biochemicals used in bio-medical applications, and easy movement purely due to capillary forces ensuring no external devices are needed to enable the ow of the reagent or analyte in the channels.…”

Section: Introductionmentioning

confidence: 99%

Microfluidic paper device for rapid detection of aflatoxin B1 using an aptamer based colorimetric assay

et al. 2020

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“…Recent examples of applications using µPADs have demonstrated the ease in coupling with different detectors, including mass spectrometry [ 12 , 13 ], chemiluminescence [ 14 ], fluorescence [ 15 ], electrochemical methods [ 16 , 17 , 18 ], and colorimetric detection [ 6 , 19 , 20 ]. The latter offers instrumental simplicity and portability, once digital images can be recorded through popular electronic devices like smartphones, digital cameras, or scanners [ 6 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

“…As recently observed in the literature, the combination of smartphones and microfluidic devices has promoted a real explosion in the number of publications, and it is a global trend—especially in laboratories with limited resources or restricted access to sophisticated infrastructure. However, the main challenges associated with colorimetric detection by smartphone are external light control and the technical ability of the user to capture images, which can both compromise the reliability of the analytical response [ 20 , 21 ]. Some apps—which are not very widespread in publications associated with microfluidics—are dedicated to colorimetric detection (e.g., Colormeter ® and Photometrix ® ).…”

Section: Introductionmentioning

confidence: 99%

Monitoring Acid–Base Titrations on Wax Printed Paper Microzones Using a Smartphone

et al. 2017

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This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i) strong acid versus strong base; (ii) strong base versus strong acid; and (iii) weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid–base titration at a confidence level of 95%. The acid–base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 µL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation.

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Evaluation of Digital Image Capture Devices for Colorimetric Detection on Printed Microzones

Cited by 8 publications

References 0 publications

Colorimetric determination of nitrite in clinical, food and environmental samples using microfluidic devices stamped in paper platforms

Colorimetric determination of nitrite in clinical, food and environmental samples using microfluidic devices stamped in paper platforms

Microfluidic paper device for rapid detection of aflatoxin B1 using an aptamer based colorimetric assay

Monitoring Acid–Base Titrations on Wax Printed Paper Microzones Using a Smartphone

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