Table.2.

Examples of some biological elements detection using IO based biosensors.

Bio-sensing method	IO material	A pore size	Detected target	LOD	General advantages of developed IO	Ref.
Photoelectrochemical	TiO2	300 nm	H2O2	70.04 A/mM	Excellent photoelectrical property and the large effective surface	[80]
Nonenzymatic	CIORs	222 nm	Cholesterol	0.5 mg/mL	UV–vis spectrometer	[158]
Aptasensor	Hydrogel	200–300 nm	Bacteria	100 CFU/mL	Rapid and sensitive detection for hematological infections	[156]
Optical	TiO2 Or SiO2	223–273 nm	Ethanol	Not mentioned	Being useful for detecting the ethanol	[160]
Optical	SiO2IO- capillaries	260 nm	Creatinine	0.9 mg/dL.	Making nanostructured capillary tubes for SERS analysis in a flow-through fashion.	[87]

NW: nanowire; SERS: Surface enhanced Raman spectroscopy. IOs: Inverse opals, CIORs: carbon inverse opal rods, CFU: colony-forming unit.