Analytical parameters for detection of metal ions using paper-based chemosensors and digital image-based colorimetric analysis.

Detection principle	Sensor	Metal Ion	L D (μM)	Ref.
Absorbance	Cubic mesocage sensors	Cd2+	0.0307	42
Absorbance	Cd2+ chemosensors	Cd2+	0.19	43
Absorbance	Dithizone TiO2 sensor	Cd2+	0.0156	44
Absorbance	Aluminosilica optical sensor	Cd2+	0.0024	45
		Co2+	0.0028
Absorbance	Green AuNP probe	Cd2+	0.03	46
Absorbance	Functionalized AuNP	Cd2+	0.0629	47
Absorbance	Azo-HNTA probe	Co2+	0.77	48
Absorbance	CpAD probe	Co2+	0.0066	49
Absorbance	Chemosensor for cobalt	Co2+	1.8	50
Absorbance	Chemosensor (HL) based on coumarin	Co2+	0.31	51
Fluorescence	Eu(iii)-organic framework	Fe3+	23	52
Fluorescence	Uranyl organic framework	Fe3+	0.0992	53
Fluorescence	Eu3+post-functionalized UiO-66	Fe3+	12.8	54
Colorimetric	Multicomponent sensor	Fe3+	1.26	55
Fluorescence	Aryl hydrazones of β-diketones	Ni2+	7	56
Absorbance	Alizarin complexone	Ni2+	40	57
Fluorescence	Hydrazine carbothioamide	Ni2+	0.079	58
Absorbance	Quinoline derivative	Ni2+	0.22	59
Absorbance	Chalcone based ratiometric chemosensor	Ni2+	5.14	60
Absorbance	Paper based chemosensors (PBCs) using spectrophotometry	Cd2+	0.13	This work
		Co2+	0.22
		Ni2+	0.015
		Fe3+	0.022
Absorbance	Paper based chemosensors (PBCs) using digital image-based colorimetric analysis (DICA)	Cd2+	0.22	This work
		Co2+	0.28
		Ni2+	0.44
		Fe3+	0.54