Optical Sensor for Bacterial Detection Through Color Change in Culture Medium

The rapid and accurate detection of bacteria is essential in medicine, the food industry, and environmental monitoring. This study presents the development of an optic sensor based on color changes in the culture medium, leveraging the optical interaction of bacterial metabolic products. The proposed prototype operates on the principle of optical transmittance through mannitol salt agar (MSA), a selective medium for Staphylococcus aureus. As bacterial growth progresses, the medium undergoes a visible color change, which is optically measurable at specific wavelengths. The sensor demonstrated the ability to detect bacterial growth within approximately 120 minutes, offering a significant reduction in detection time compared to traditional incubation methods. The system is characterized by its simplicity, sensitivity, low reagent consumption, and potential for real-time monitoring. These findings support the feasibility of the proposed sensor as an efficient alternative for early pathogen detection in both clinical and industrial contexts.