TABLE 2.

Requirements for an ideal bacterial biosensor

Parameter	Value or quality
Sensitivity	Less than 103 CFU/ml
Specificity	Can distinguish different serotypes of bacteria (e.g., can distinguish E. coli Nissle 1917 from E. coli O157:H7), minimal background, must operate in complex matrices (e.g., clinical samples such as sputum and blood, food, and beverage samples)
Speed	5–10 min for a single test
Size	Compact, portable device that can operate at the site of interest
Sample processing	Label free with minimal sample processing
Stability	Biorecognition element must be stable at the high temperatures experienced in some countries (e.g., up to 45°C) for several months to allow for good shelf life
Skill of operator	No specialist training needed to use the assay, can be used by patients