Table 4.
Nanoprobes and sensors for detecting superoxide anion radical.
| Type of Material | Probe | Detection Type | LOD | Linear Range | Advantages/Disadvantages | Ref. |
|---|---|---|---|---|---|---|
| Carbon-dots | Hydroethidine | Fluorometric (λex = 488 nm/ λem = 525 nm) |
100 nmol·L−1 | 5 × 10−7–1.4 × 10−4 mol·L−1 | Advantage: -Selective to O2•− Disadvantage: -Could not be sensitive for quantification of O2•− |
[92] |
| Ag@SiO2 core/shell nanoparticles | 2-chloro-1,3-dibenzothiazoline cyclohexene (DBZTC) | Fluorometric | 0.73 nmol·L−1 | - | Advantage: -Sensitive detection towards other ROS (very high selectivity over hydrogen peroxide) -Applicable to living cells Disadvantage: Relatively low selectivity over NO• and ONOO‒ |
[96] |
| Silica Sol-gel glass | Amplex Red-H2O2 (in SOD/HRP enzyme system) | Fluorometric (λexc = 530 nm/λem = 590 nm) |
20 nmol·L−1 | ≤1.0 × 10−6 mol·L−1 of xanthine | Advantage: -This biosensor has ready-to-use and reusable properties Disadvantage: -The sensor is not expected to be of use in biological media where the concentration of hydrogen peroxide is relatively higher than that of superoxide |
[97] |
| Gold nanoparticles | Cytochrome c | Surface Enhanced Raman Scattering (SERS) | 10 nmol·L−1 | 2.3 × 10−8–2.8 × 10−6 mol·L−1 | Advantage: -Suitable for qualitative/quantitative analysis of O2•− in biosystems -The other ROS do not interfere with the method Disadvantage: -SERS signals may show relatively high RSD values |
[99] |
| CdSe/ZnS quantum-dots | Cytochrome c | Fluorometric | - | 0.08–1.49 μmol·L−1 | Advantage: -High selectivity and specifity in living cells -Low cytotoxicity Disadvantage: -Cytochrome c may be reduced by a variety of biological electron carriers other than superoxide |
[101] |
| Suffocated polystyrene nanoparticles/terbium-guanine nanoscale coordination polymers (PS-SO3H@Tb/G NCPs) |
Terbium(III) | Fluorometric | 3.4 nmol·L−1 | 10.12 nmol·L−1–6.0 μmol·L−1 | Advantage: -High selectivity |
[104] |