Simple and rapid determination of cephalexin by digital colorimetry using a laboratory-developed smartphone application

Abstract

A simple and fast method for determination of cephalexin using test papers with immobilized Fehling's reagent is reported. Color scales for the naked-eye determination of cephalexin were constructed. Based on RGB-analysis linear correlations between the intensities of the blue and green color channels, the concentration of cephalexin were obtained. Furthermore, the possibility of using radar charts for the analyte was investigated. For detection of antibiotic, the authors’ application for smartphone «Digital colorimetric test» was created. After loading a photo of the paper-based device, the application automatically displays the concentration of antibiotic on the screen. Moreover, for detection of the antibiotic, a small volume of sample (5 μL) is required. The limits of detection for developed methods were from 0.13 to 0.4 mg/mL (Sr < 0.12).

KEYWORDS:

• Cephalexin
• antibiotic determination
• phone camera detection
• digital colorimetry
• paper-based device

Conflict of interest

The authors declare no conflicts of interest.

Additional information

Funding

The reported study was funded by RFBR according to the research project № 20-33-90020.