High sensitive and selective Escherichia coli detection using immobilized optical fiber microprobe

Abstract

We proposed and demonstrated a stable, label-free bacteriophage-based sensor of Escherichia coli using microfiber probe. T4 Bacteriophage was covalently immobilized on microfiber surface and E.coli concentration was investigated using the high accurate spectral interference mechanism. By immersing microfiber sensor into different concentration E.coli solution, the relationship between resonant wavelength shift and E.coli concentration was analyzed in the range of 103–107cfu/ml. The proposed method is capable of reliable detection of E.coli concentration as low as 103cfu/ml with a fast response time about 10 minutes, which makes the real-time detection of E.coli move on a giant step. Additionally, the sensor has great potential to be applied in the fields like environment monitoring and food safety.