Table 7.

Colorimetric biosensors developed for detecting illicit drugs.

Type of analyte	Type of substrate	LOD (nM)	MRPLc (ng/mL)	Ref.
CBa	Ag NPs	2.8 × 10−2	0.2	[173]
CB	Au NPs	50	0.2	[172]
CB and Ractopamine	Ag NPs	5.7 × 104a and 6.1 × 105b	0.2 & 3	[153]
PBc	Ag NCs	4.205 × 103	250	[157]
Cocaine	Au NPs	1	100	[177]
MA & MDMA	Au NPs	Low micromolar range	500	[178]

^dWADA general Minimum Required Performance Limit (MRPL) values.

^aFor CB.

^bFor Ractopamine.

^cProbenecid.