Development of miniaturized fluorimetric device for caffeine determination using a smartphone

Author(s)

Luchiari, Natalia da Costa ^[1] ; da Silva, Gabrielen Alves ^[1] ; Marasco Junior, Cesar Augusto ^[1] ; Feitosa de Lima Gomes, Paulo Clairmont ^[1]

Affiliation

^[1] UNESP, Natl Inst Alternat Technol Detect Toxicol Evaluat, Inst Chem, Dept Analyt Chem, POB 355, BR-14800900 Araraquara, SP - Brazil

• Document type: Journal article
• Source: RSC ADVANCES; v. 9, n. 60, p. 35033-35038, OCT 30 2019.
• Web of Science Citations: 0

Abstract

Caffeine is an element that is consumed worldwide. It is present in many products such as beverages, chocolate, coffee, tea, energy drinks and medicines. Portable 3D devices working together with colorimetric and fluorimetric reactions have been able to determine the presence of caffeine in different kinds of samples. Also, digital image-based methods using smartphones have conferred portability and accessibility to miniaturized devices that are innovative and promising options for quick and low cost analyses. This study proposes a miniaturized fluorimetric device to determine caffeine by digital image using a smartphone. The OpenCamera app was used to capture images that were processed using ImageJ software to obtain RGB channels values. The red (R) channel signal intensity was selected as the analytical response. The device developed was applied to determine caffeine in an energy drink and medicines. The method developed presented a linear range from 100 to 600 mg L-1 of caffeine, and quantification (LOQ) and detection (LOD) limits of 100 mg L-1 and 30.0 mg L-1, respectively. The caffeine concentration found in the products analyzed was 328 mg L-1 (+/- 2.5%) for the energy drink, 345 mg L-1 (+/- 15%) for medicine A and 322 mg L-(1) (+/- 7.3%) for medicine B. The proposed device presented important characteristics such as low cost, required small volumes of reagents and samples, quick analysis, portability and suitable to be applied in complex matrices. (AU)

• FAPESP's process: 18/22393-8 - Biochar applied in the removal of emerging contaminants present in wastewater
• Grantee: Paulo Clairmont Feitosa de Lima Gomes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/03369-3 - Development of paper-based microfluidic devices for pharmaceuticas analysis in wastewaters.
• Grantee: Paulo Clairmont Feitosa de Lima Gomes
• Support Opportunities: Regular Research Grants