Table 2.

List of different Techniques used in lead detection.

Class	Reagent (support matrix)	Method	Signal Properties	Detection Limit	Range	Selectivity	Year	Ref
Electrochemical	Bi-SPE	ASV	N/A	0.15 ppb	0.5 – 100 ppb	unknown	2011	69
	G-quadruplex with crystal violet	DPV	N/A	82.2 ppt	0.2 – 205 ppb	good	2011	70
	1,10-phenanthroline	ASV	N/A	82.2 ppt	N/A	nonspecific	2011	72
	DNA/C-TiO2 NTs	ASV	TiO2	0.7 ppt	2.1 ppt – 32.8 ppb	good	2010	71
	carbon composite PVC-based membrane	ASV	Pt wire	65.8 ppb	0.158 – 20,548 ppm	good	2010	73
Nanoparticles	Au nanoparticles	Fluorescence Absorbance	Ex: 330nm Em: 600nm	247 ppb	N/A	poor	2012	74
	Au nanoparticles and DNAzymes	DLS	Adsorption at ~540 nm	1.3 ppt, 7.2 ppt	2.1 – 61.1 ppt	good	2012, 2011	85,86
	CdTe-QDs	Fluorescence	Ex: 525nm Em: 560nm (QY =0.07)	30 ppb	0.22–4.51 ppm	good	2009	75
DNAzymes	cationic polythiophene (PT) DNAzyme	Fluorescence	N/A	0.2 ppb	0.002 – 20 ppm	good	2012	82
	DNAzyme with graphene oxide	Fluorescence	Em: ~565 nm	100 ppt	N/A	good	2011	79
	Computer-Readable DNAzyme on Disc	Error Distribution of CD	N/A	2ppb	0.002–205 ppm	good	2011	81
	GR-5DNAzyme	Fluorescence	N/A	0.76 ppb	N/A	good	2010	78
	DNAzyme in amicrofluidic device	LIF	Ex: 488 nm Em: 518 nm	2.3 ppb	0.020.5 – 20.5 ppm	good	2005	80
	DNAzyme-Au-NPs	Absorbance	Abs: 522 & 700 nm	can be tuned	can be tuned	good	2003	77
Small Molecules	Calix-DANS3-OH (PDMS microfluidic chip)	Fluorescence	Ex: 365 nm Em: 496 nm	42ppb	N/A	good	2012	102
	triazolo-thiadiazi (imbedded in PVC)	Fluorescence	Ex: 330 nm Em: 430 nm QY=0.039	4.5 ppb	0.010.2 – 78.1 ppm	good	2011	99
	PDA-polymer	Fluorescence	Ex: 254nm Em: 540 nm	0.8 ppm	N/A	good	2011	104
	LFS-1	Fluorescence	Em: 469 nm	N/A	N/A	good	2011	105
	L2 (immobilized on PVC)	Fluorescence	N/A	41 ppb	0.062 – 5137 ppm	N/A	2010	106
	Arsenazo III (immobilized on XAD-16)	Reflectance	N/A	10 ppb	0.205–20.5 ppm	N/A	2010	107
	Lead-selective ionophore (immobilzed on PVC)	Absorbance	N/A	5 ppb	0.007 – 10.7 ppm	N/A	2010	108
	BODIPY-functionalized Fe3O4.SiO2 nanoparticles	Fluorescence	Ex: 326&596 Em: 456 nm (QY=0.042)	1.5 ppb	0 – 30 ppb	good	2010	109
	Calix-DANS4	Fluorescence	Ex: 365 nm	5 ppb	N/A	N/A	2009	101
	1,8-diaminoanthraquinone	Absorbance	Abs: 524 nm	Eye: 2–3 ppm UVvis: 21 ppb	N/A	good	2009	98
	Imine-bridged TTF-pi-Py	Absorbance and Electrochemical	Abs: 508 nm	micromolar	N/A	Zn2+ interferes	2009	110
	Leadglow (LG)	Fluorescence	Ex: 389 nm Em: 423 nm	10 ppb	1 –50 ppb	good	2009	100
	LF1	Fluorescence	LF1:Pb2+: Em:514 (QY=0.013)	<15 ppb	N/A	good	2006	97
	Ketoaminocoumarin (solution)	Fluorescence	Ex: 411nm Em:491 (QY=0.35)	N/A	N/A	good	2002	96

Selectivity: good (Mn²⁺, Mg²⁺, K⁺, Fe²⁺, Fe³⁺, Co²⁺, Cd²⁺, Al³⁺, Ag⁺, Zn²⁺, Ca²⁺, Ba²⁺, Sr²⁺, and Hg²⁺), N/A (unknown - not known or only a few metal ions tested), nonspecific.