Table 2.
Applications of the detection of metal ions by PADs and microPADs using luminescent nanomaterials as receptors.
| Target Analyte | Sample/Matrix | Nanostructured Receptor | Sensor Design | Signal Acquisition | Analytical Characteristics | Ref. |
|---|---|---|---|---|---|---|
| Se(IV) | Hair, sediment, urine | CdTe QDs | PAD | Fluorescence under UV irradiation |
0.1 ppb Se | [72] |
| Hg(II), Pb(II), Cu(II) |
River water | CDs | PAD (microarray) |
Smartphone | 5.8 nM (Hg) 0.12 µM (Pb) 0.076 µM (Cu) |
[73] |
| Hg(II) | Wastewater | GQDs (N, S-codoped) |
PAD | Digital camera (UV irradiation) |
0.14 nM | [74] |
| Ce(III) | River water | Carbon dots | PAD | Naked eye (UV irradiation) |
0.7 µM (fluorimetry) |
[75] |
| Fe(III) | -- | N-doped GQDs | PAD | Naked eye (UV irradiation) |
2.37 µM (fluorimetry) |
[76] |
| Hg(II) | Water, urine | CdSe/ZnS QDs (functionalized with HDTC) |
PAD | Naked eye (UV irradiation) |
0.2 ppm Hg | [77] |
| Ag(I), AgNPs | River water | CdTe QDs | PAD | Naked eye (UV irradiation, distance measurement) |
0.01 ppm (Ag) | [78] |
| Se(IV) | Tap water, seawater fish, rice, eggs |
AuNCs | PAD | Naked eye (UV irradiation) and fluorimetry |
4 ppb (Se) | [79] |
| Al(III) | ---- | C-dots-R6G | PAD | Digital camera (UV irradiation) and fluorimetry |
3.89 × 10−5 M (PAD) | [80] |
| Tri-butyl-Sn | Seawater | GQDs conjugated with MIN |
PAD | Fluorimetry | 0.23 ppt | [81] |
| Hg(II), Cu(II) | Tap and river water |
CS-CDs | Sponge cellulose |
Mobile camera (UV irradiation) |
26 nM (Al); 0.11 and 3 µM (Cu), by fluorimetry and PAD, resp. |
[82] |
| Cu(II) | Tap water, Lake water |
Hybrid CdTe-CDs | PAD | Digital camera (UV irradiation) |
0.36 nM (fluorimetry) |
[83] |
| Cu(II) | Urine, tap water, Sorghum extract |
BSA-AuNCs | PAD | Naked eye (UV irradiation) |
5 nM (fluorimetry) |
[84] |
| Cu(II), Hg(II) | Tap water | N-doped CDs | µPAD | Digital camera (UV irradiation) |
0.1 µM (µPAD); 6.2 nM (Hg), 2.3 nM (Cu) by fluorimetry |
[85] |
| Cu(II), Hg(II) | Tap and lake water | CQDs | PAD | Naked eye | 5 (Cu), 3 (Hg) (µM) | [86] |
| Zn(II) | Water, blood, cells | AuNCS | PAD | Naked eye and fluorimetry |
3 ppb (fluorimetry) 20 ppb (naked eye under UV irradiation) |
[87] |
| Co(II) | --- | ZnS QDs | PAD | Mobile camera | 10 ppm | [88] |
| Cu(II) | -- | ZnO NPs | PAD | Mobile camera | 10 µM | [89] |
| Hg(II) | Tap water Lake water |
CDs | PAD | Naked eye (UV irradiation) |
0.14 µM | [90] |
| Pb(II) | --- | CDs | PAD | Fluorimetry and naked eye |
0.055 µM (fluorimetry) |
[91] |
| Pb(II) | Waters | CDs | PAD | Fluorimetry and smartphone camera |
2.89 nM (fluorimetry) 45.9 nM (PAD) |
[92] |