Evidence map›Paper›PMID 40968793›Full record

ArticleSensors (Basel, Switzerland)2025

Color QR Codes for Smartphone-Based Analysis of Free Chlorine in Drinking Water.

María González-Gómez, Ismael Benito-Altamirano, Hanna Lizarzaburu-Aguilar, David Martínez-Carpena, Joan Daniel Prades, Cristian Fàbrega

Abstract read
In one paragraph

Article in Sensors (Basel, Switzerland), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

María González-GómezDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.ORCID 0000-0002-1286-8398
Ismael Benito-AltamiranoDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.ORCID 0000-0002-2504-6123
Hanna Lizarzaburu-AguilarDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.
David Martínez-CarpenaDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.ORCID 0000-0001-9452-5315
Joan Daniel PradesDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.ORCID 0000-0001-7055-5499
Cristian FàbregaDepartment of Electronic and Biomedical Engineering, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.ORCID 0000-0001-8337-4056

Funding

Agència per la Competitivitat de l'Empresa - ACCIÓ INNOTECRD19 1 0002Eurorepan Research Council - H2020 Framework Programe 951774Eurorepan Research Council - H2020 Framework Programe 957527Ministerio de Ciencia, Innovación y Universidades PID2022 138721NB I00
6 · The paper itself

Abstract

Free chlorine (FC) plays a crucial role in ensuring the safety of drinking water by effectively inactivating pathogenic microorganisms. However, traditional methods for measuring FC levels often require specialized equipment and laboratory settings, limiting their accessibility and practicality for on-site or point-of-use monitoring. QR Codes are powerful machine-readable patterns that are used worldwide to encode information (i.e., URLs or IDs), but their computer vision features allow QR Codes to act as carriers of other features for several applications. Often, this capability is used for aesthetics, e.g., embedding a logo in the QR Code. In this work, we propose using our technique to build back-compatible Color QR Codes, which can embed dozens of colorimetric references, to assist in the color correction to readout sensors. Specifically, we target two well-known products in the HORECA (hotel/restaurant/café) sector that qualitatively measure chlorine levels in samples of water. The two targeted methods were a BTB strip and a DPD powder. First, the BTB strip was a pH-based indicator distributed by Sensafe

Indexed as

ChlorineDrinking WaterSmartphoneColorColorimetryChlorineDrinking Watercolorimetric analysiscomputer visionfree chlorinemachine learningQR Codewater quality

Identifiers

PMID40968793
PMCPMC12157797

What OpenQuestion holds

Textmetadata
LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.