“Time to onset of positive detection” (in minutes) for two species of Listeria at different injection concentrations.

Initial concentration (CFU mL−1)	Strain	Number of experiments	Time to onset of positive detection (in min)
			SPRI sensorgrams			Event counting using RO-SPRI
			Lis12	LiM16	LiM14	Lis12	LiM16	LiM14
2 × 102	L. monocytogenes	n = 2	—	518 ± 2	528 ± 6	—	432 ± 15	440 ± 17
3 × 104	L. monocytogenes	n = 2	—	306 ± 6	306 ± 6	—	236 ± 6	236 ± 6
3 × 104	L. innocua	n = 2	312 ± 8	—	—	246 ± 9	—	—
3 × 104	L. monocytogenes & L. innocua	n = 1	318	316	312	247	247	243