Table 1.

Comparison of different E. coli detection methods with fluorescent signal output in recent years

Target	Method	Limit of detection	Linear range	Reaction time
Extracellular proteins (29)	DNAzyme	${10}^3$ CFU/μL	–	Mix and read
Cell/lipopolysaccharides (30)	Aptamer	487 CFU/mL	500-${10}^6$ CFU/mL	40 min
Cell/mycoproteins (31)	Polyclonal antibody	${10}^3$ CFU/mL	${10}^3$–${10}^5$ CFU/mL	25 min
Target gene (32)	PCR	10 copies	10-${10}^5$ copies	100 min
Target gene (33)	RPA	100 copies	${10}^2$–${10}^7$ copies	13 min
Whole genome (present work)	Designed primers	$\sim$5 copies/mL	10-${10}^{10}$ copies/mL	Mix and read

Here, PCR, RPA for recombinase polymerase amplification, and CFU for colony-forming units. The number of CFU is typically less than the number of microorganisms deposited on a plate containing growth medium.