Efficient and Rapid Detection of Salmonella Using Microfluidic Impedance Based Sensing

We present a low cost, easy to fabricate biosensor, which can quickly and accurately detect Salmonella typhimurium. This study also compares the advantages of the microfluidic biosensor over a nonmicrofluidic biosensor. High density interdigitated electrode array was used to detect Salmonella cells inside a microfluidic chip. Monoclonal anti-Salmonella antibodies were allowed to be immobilized on the surface of the electrode array for selective detection of Salmonella typhimurium. An impedance analyzer was used to measure and record the response signal from the biosensor. The biosensor provides qualitative and quantitative results in 3 hourswithout any enrichment steps.Themicrofluidic biosensor’s lower detection limitwas found to be 3×103 CFU/mL compared to the 3×104 CFU/mL of the nonmicrofluidic biosensor, which shows that themicrofluidic biosensor has 10-fold increased sensitivity. The impedance response of microfluidic biosensor was also significantly higher (2 to 2.9 times) compared to the nonmicrofluidic biosensor.