MoS2/TiO2 Hybrid Nanostructure-Based Field-Effect Transistor for Highly Sensitive, Selective, and Rapid Detection of Gram-Positive Bacteria

Field-effect transistor (FET) biosensors based on hybrid nanostructures present unique advantages of high sensitivity, small size, excellent dynamic range, and compatibility with integrated circuits. In this work, the fabrication of highly sensitive and selective hybrid MoS2/TiO2 nanostructure-based FET is demonstrated for the detection of Gram-positive bacteria. The fabricated FET biosensors are efficiently capable of discriminating between Gram-positive and Gram-negative bacteria with a limit of detection 50 cfu mL(-1). The biosensor exhibits a high sensitivity of 49.47 +/- 1.7% for Staphylococcus aureus among eight different bacteria at a concentration of 10(2) cfu mL(-1). The real time detection of bacteria with a response time of 22.19 s is achieved at concentrations as low as 50-100 cfu mL(-1), suggesting rapid and low concentration detection of selective bacteria. The FET biosensor is also able to quantify bacteria in the physiological conditions as well as discriminate between live and dead bacteria. The unique hybrid nanostructure based FET with desirable biosensing properties presents the potential to screen the pathogenic bacteria. Live/dead monitoring of bacteria may help in deciding the course and dosage of the antibiotic treatment.