. 2021 Jul 9;11(7):1792. doi: 10.3390/nano11071792

Table 5.

Representative studies of probed-based detection of heavy metals from food and water resources by nanosensors.

Electrode	Analytical Technique	Sample	Linear Range	Limits of Detection	Aptamer Sequence	Ref.
AuNPs-aptamer	Colorimetry	Water samples	/1 nM–0.1 mM Hg²⁺	0.6 nM Hg²⁺	5′-TTTTTTTTTT-3′(Hg²⁺); 5′-CCAACCACAC-3′ (Control random oligonucleotide sequence)	[115]
FMs/AuNPs-aptamer	Fluorometry	River water samples	0.13–4 ng/mL Hg²⁺	0.13 ng/mL Hg²⁺	MRP: 5′-biotin-AAA AAA AAA ATT CTT TCT TCC CCT TGT TTG TT-3′; T-line Probe1: 5′-biotin-AAA AAA AAA ACA CAA ACA AGG CCA ACA-3′	[117]
(AuNPs/CS)₂-GCE- aptamer	Electrochemical	Tap water samples	0.01–500 nM Hg²⁺	0.005 nM Hg²⁺	5′-HS-(CH₂)₆-TCA TGT TTG TTT GTT GGC CCC CCT TCT TTC TTA-Fc-3′	[119]
GSH/AgNPs (Cys)	Colorimetry	Water samples	0.4–4.0 μM Al³⁺	1.2 μM (eyes) Al³⁺ 0.16 μM (UV) Al³⁺	/	[122]
AgNPs/NaCysC	Colorimetry	Tap water and drinking water	5–50 nM Hg²⁺	8 nM Hg²⁺	/	[124]
CdS (QDs)/GSH	Fluorometry	Industrial wastewater sample	10 nM–20 μM Cd²⁺	0.54 nM Cd²⁺	/	[127]
CdSe (QDs) Bacillus licheniformis cells	Fluorometry	Complex solution environment	0–20 μM Cu²⁺	0.91 μM Cu²⁺	/	[130]
DNA/Fe₃O₄/AuNPs/MGCE	Electrochemical	Taihu Lake water, drinking water, orange juice and red wine sample	10–150 nM Ag⁺ 10–100 nM Hg²⁺	3.4 nM Ag⁺ 1.7 nM Hg²⁺	DNA1 (thiolate), DNA2 (Fc and MB)	[133]
Fe-MOF/mFe₃O₄mC-aptamer	Electrochemical	River water samples	0.01–10.0 nM Pb²⁺	2.2 pM Pb²⁺	5′-CAA-CGG-TGG-GTG-TGG-TTGG-3′	[136]
Fe-MOF/mFe₃O₄mC-aptamer	Electrochemical	River water samples	0.01–10.0 nM As³⁺	6.73 pM As³⁺	5′-GGT-AAT-ACG-ACT-CAC-TAT-AGG-GAG-ATA-CCA-GCT-TAT-TCAATT-TTA-CAG-AAC -AAC-CAA-CGT-CGC-TCC-GGG-TAC-TTC-TTC-ATC-GAG-ATA-GTAAGT-GCA-ATCT-3′	[136]
Au-PWE/((Fe-P)n-MOF-Au-GR)	Electrochemical	Water, fruit juice soil sample	0.03–1000 Pb²⁺	0.02 Pb²⁺	/	[138]
PDA/rGO/DNA/GCE	Electrochemical	Kunyu River sample	8–100 nM Hg²⁺	5 nM Hg²⁺	Probe DNA (NH²⁻ssDNA: 5′-NH²⁻(CH₂)₆-GAT-TCC-GTG-CAT-GAC-TCA-G-3′) Target DNA (4-Mis DNA:5′-C-TGT-GTC-TTG-CTC-GGT-ATC-3′) Control DNA (5′-GAT-TCC-GTG-CAT-GAC-TCA-G-3′)	[141]
GO/aptamer- CdSe/ZnS (QDs)	Fluorometry	River water samples	0.1–10 nM Pb²⁺	90 pM Pb²⁺	5′-NH₂⁻(CH₂)₆–GGGTGGGTGGGTGGGT–3′	[142]
GO/Au electrode (Thiol-PTO)	Electrochemical	Drinking water	1–300 nM Hg²⁺	1 nM Hg²⁺	(Thiol-PTO) (SH-C₆-5′TTT-TTT-TTT-TTT-TTT-TTT-TTT-TTT-TTT-TTT-3′)	[145]
Long strand aptamer UCNPs/AuNPs-Short strand aptamer	Fluorometry	Tap water and milk samples	0.2–20 μM Hg²⁺	60 nM Hg²⁺	5’NH₂C₆-CTA CAG TTT CAC CTT TTC CCC CGT TTT GGT GTT T-3′ (Long stranded aptamer), (short-stranded aptamer) 5’SHC₆-GAA ACT GTA G-3’	[148]
CQDs/AuNPs/GSH	Colorimetry	Environmental Water samples	10–300 nM Hg²⁺	7.5 nM Hg²⁺	/	[149]

Abbreviations: Au nanoparticles (AuNPs), latex fluorescent microspheres (FMs), chitosan (CS), glassy carbon electrode (GCE), glutathione (GSH), L-cysteine (Cys), Sodium salt of N-cholyl-L-cysteine (NaCysC), cadmium sulfide (CdS), magnetic glassy carbon electrode (MGCE), Fe³⁺-based metal–organic framework (Fe-MOF), DNA (GR) functionalized iron porphyrin metal organic framework (Fe-P)n-MOF-Au-GR), gold nanoparticle modified paper electrode (Au-PWE), polydopamine (PDA), quantum dots (QDs), poly-T-oligonucleotides (PTO), up-conversion nanoparticles (UCNPs).