Table 1 . Examples of various types of immunosensors for opiate drugs with its detection limit .

Name of immunosensor	Drug Name	Limit of detection	Reference
Piezoelectric	Cocaine	34 ng/l	52
	Cocaine & Ecstasy	100 & 200 ng	53
Micromechanical	Cocaine	1 ng/mL	55
	MDMA	5 µg/mL	56
Electrochemical	Cocaine	0.005 µg/mL	63
	Morphine	0.2-1.2 mM	58
Carbon Nanotube	MAM	15pg/mL	43
	Morphine	0.01 mM; 0.01 µM	54,59
Optical	Heroin & its metabolites	1-1.4 ng/mL	9
	Opiate drugs	2.5 ng/mL	10
	M-3-G	3-97 ng/mL	18
	MDMA & Ecstasy	20 ng/mL & 0.2 ng/mL	61
	Morphine	2000 ng/mL	60
	Morphine	0.1 nM	64
Aptamer	Cocaine	2 nM	48
	Codeine	3 pM	62