Table 2. Summarized Examples of the Use of Quantum Dots in PEC Biosensorsa.
| QDs | λmax emission (nm) | capping | modifications and functionalization | modification method | size (nm) | target | cell line | LOD value (mol L–1) | ref |
|---|---|---|---|---|---|---|---|---|---|
| CdSe | TGA | DNA | carbodiimide coupling (EDC/NHS) | 3 | miRNA-21 | 5.6 × 10–15 | (119) | ||
| CdTe | 4 | miRNA-141 | 33 × 10–18 | (120) | |||||
| CdTe | MPA | C3N4; 3D graphene hydrogel | carbodiimide coupling (EDC/NHS) | miRNA-21; miRNA-141 | (121) | ||||
| CdTe | MPA | CeO2 | carbodiimide coupling (EDC/NHS) | miRNA-141 | 0.17 × 10–15 | (122) | |||
| CdSe | MPA | nitrogen-doped porous carbon-ZnO polyhedral | 5 | miRNA-155 | 49 × 10–18 | (117) | |||
| ZnS | MPA | manganese-doped cadmium sulfide | 3 | miRNA-141 | 3.30 × 10–15 | (123) | |||
| PbS | TGA | DNA | carbodiimide coupling (EDC/NHS) | 5 | miRNA-21 | 0.57 × 10–15 | (124) | ||
| CdTe | 526 | MPA | DNA | carbodiimide coupling (EDC/NHS) | 3.0 ± 0.8 | miRNA-21 | 0.37 × 10–15 | (125) | |
| CdTe | MPA | DNA | 5 | miRNA-21 | MCF-7; HeLa | 3.3 × 10–15 | (49) | ||
| CdS | MPA | DNA | carbodiimide coupling (EDC/NHS) | 4 | miRNA-21 | breast cancer | 6.6 × 10–15 | (126) | |
| let-7a | 15.4 × 10–15 | ||||||||
| CuS | TGA | DNA | carbodiimide coupling (EDC/NHS) | miRNA-21 | 3.25 × 10–15 | (127) | |||
| CdS | 3 | miRNA-141 | 0.33 × 10–15 | (128) |
a
TGA, thioglycolic acid; MPA, 3-mercaptopropionic acid; DNA, deoxyribornucleic acid; EDC, 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride; NHS, N-hydroxysuccinimide; miRNA, micro ribonucleic acid.