Table 1.

Comparison of optical biosensors.

Device	Mass Detection Limit (pg/mm2)	RI detection Limit (RIU)	Waveguide Structure	Waveguide Material	Reference
Interferometric
MZI	0.06	1 × 10−7	Rib	Si3N4	[21]
	0.25	ND*	Ridge	SOI	[23]
Young	0.75	9 × 10−8	Rib	SixOyNz	[42]
	0.013	9 × 10−9	Slab	Ta2O5	[48]
Bimodal WG	0.05	2.5 × 10−7	Rib	Si3N4	[52]
Ring resonator	1.5	7.6 × 10−7	Ridge	SOI	[63]
	ND	8.3 × 10−6	Ridge	SOI	[69]
Photonic crystal	0.42	3.4 × 10−5	2D	Si3N4	[77]
	ND	7 × 10−6	Slot	SOI	[94]

* ND not determined.