Research Article

A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques

Volume: 2026 Number: 2 June 3, 2026

A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques

Abstract

Creatinine is an essential biomarker for assessing kidney function. This study presents a novel diazonium-based colorimetric method for measuring creatinine in human serum, utilizing both traditional spectrophotometry and a microfluidic detection platform. The technique involves the in situ formation of a diazonium salt (generated with acidified sodium nitrite), which reacts with p-phenylenediamine and α-naphthol to form a stable reddish-violet azo dye. The absorbance of this dye correlates directly with creatinine levels. The spectrophotometric method was optimized to detect maximum absorbance at 524 nm, while the microfluidic method was optimized with a smartphone-based colorimetric app. Calibration curves showed excellent linearity (R² = 0.9980 for 1.0–10.0 mg/dL, R² = 0.9983 for 2.0–14.0 mg/dL with both methods). The detection and quantification limits were 0.5 mg/dL (5 µg/mL) and 1.515 mg/dL (15.15 µg/mL) for spectrophotometry, and 1.2 mg/dL (12 µg/mL) and 2.62 mg/dL (26.2 µg/mL) for microfluidics. Both methods demonstrated high precision (RSDs 1.02% and 1.82%) and accuracy (recovery rates between 96.5% and 104.2%), comparable to the Cobas c311 analyzer. These results emphasize the method’s robustness, sensitivity, and suitability for both centralized lab testing and point-of-care diagnostics.

Keywords

Ethical Statement

All studies were conducted in accordance with the principles of biomedical ethics as outlined in the 1964 Declaration of Helsinki and its later amendments. They were also approved by the Research Ethics Committee of College of Science, University of Baghdad, protocol No. CSEC/0226/0021 dated February 23, 2025. Each participant in the study provided voluntary written informed consent after receiving an explanation of the potential risks and benefits and the nature of the study.

Thanks

The author would like to express their sincere gratitude to the Department of Chemistry, College of Science, University of Baghdad, for providing access to laboratory facilities and equipment.

References

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Details

Primary Language

English

Subjects

Flow Analysis

Journal Section

Research Article

Publication Date

June 3, 2026

Submission Date

November 14, 2025

Acceptance Date

April 30, 2026

Published in Issue

Year 2026 Volume: 2026 Number: 2

APA
Abduljallel, E. A., & K. Hammood, M. (2026). A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques. Journal of the Turkish Chemical Society Section A: Chemistry, 2026(2), 1-15. https://doi.org/10.18596/jotcsa.1823439
AMA
1.Abduljallel EA, K. Hammood M. A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques. JOTCSA. 2026;2026(2):1-15. doi:10.18596/jotcsa.1823439
Chicago
Abduljallel, Elaf A., and Mohammad K. Hammood. 2026. “A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques”. Journal of the Turkish Chemical Society Section A: Chemistry 2026 (2): 1-15. https://doi.org/10.18596/jotcsa.1823439.
EndNote
Abduljallel EA, K. Hammood M (June 1, 2026) A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques. Journal of the Turkish Chemical Society Section A: Chemistry 2026 2 1–15.
IEEE
[1]E. A. Abduljallel and M. K. Hammood, “A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques”, JOTCSA, vol. 2026, no. 2, pp. 1–15, June 2026, doi: 10.18596/jotcsa.1823439.
ISNAD
Abduljallel, Elaf A. - K. Hammood, Mohammad. “A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques”. Journal of the Turkish Chemical Society Section A: Chemistry 2026/2 (June 1, 2026): 1-15. https://doi.org/10.18596/jotcsa.1823439.
JAMA
1.Abduljallel EA, K. Hammood M. A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques. JOTCSA. 2026;2026:1–15.
MLA
Abduljallel, Elaf A., and Mohammad K. Hammood. “A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques”. Journal of the Turkish Chemical Society Section A: Chemistry, vol. 2026, no. 2, June 2026, pp. 1-15, doi:10.18596/jotcsa.1823439.
Vancouver
1.Elaf A. Abduljallel, Mohammad K. Hammood. A Diazonium-Based Colorimetric Approach for the Sensitive Detection of Creatinine in Serum Using Spectrophotometric and Microfluidic Techniques. JOTCSA. 2026 Jun. 1;2026(2):1-15. doi:10.18596/jotcsa.1823439