Sánchez Aramis A, Riofrío Grettel, Castillo Darwin, Padilla-Martínez J P, Lakshminarayanan Vasudevan
PROSUR Construcción Sustentable del Sur, Puebla 72810, Mexico.
Department of Chemistry, Universidad Técnica Particular de Loja, Loja 1101608, Ecuador.
Biosensors (Basel). 2025 Aug 20;15(8):551. doi: 10.3390/bios15080551.
Rapid and accurate bacterial detection is essential in medicine, the food industry, and environmental monitoring. This work presents the development of an optical sensor based on color changes in the culture medium that leverages the optical interaction of bacterial metabolic products. The proposed prototype operates on the principle of optical transmittance through mannitol salt agar (ASM), a selective medium for . As bacterial growth progresses, the medium undergoes changes in thickness and, primarily, color, which is optically measurable at specific wavelengths depending on the type of illumination provided by the simplified light-emitting diodes (LEDs). The sensor demonstrated the ability to detect bacterial growth in approximately 90-120 min, offering a significant reduction in detection time compared to traditional incubation methods. The system is characterized by its simplicity, sensitivity, low reagent consumption (up to 140 fewer reagents per test), and potential for real-time monitoring. These findings support the viability of the proposed sensor as an efficient alternative for early pathogen detection in both clinical and industrial applications. Finally, a proposal for simplifying the sensor in a system composed of a light-emitting diode and a light-dependent resistor is presented.
快速准确的细菌检测在医学、食品工业和环境监测中至关重要。这项工作展示了一种基于培养基颜色变化的光学传感器的开发，该传感器利用了细菌代谢产物的光学相互作用。所提出的原型基于通过甘露醇盐琼脂（ASM）的光学透射原理运行，ASM是一种用于……的选择性培养基。随着细菌生长的进行，培养基的厚度会发生变化，主要是颜色变化，根据简化发光二极管（LED）提供的照明类型，在特定波长下可以对颜色进行光学测量。该传感器展示了在大约90 - 120分钟内检测细菌生长的能力，与传统培养方法相比，检测时间显著缩短。该系统的特点是简单、灵敏、试剂消耗低（每次测试最多少用140种试剂）以及具有实时监测的潜力。这些发现支持了所提出的传感器作为临床和工业应用中早期病原体检测的有效替代方案的可行性。最后，提出了在由发光二极管和光敏电阻组成的系统中简化该传感器的建议。
