Table 3.
Summary of optical properties and sensing performance of AIE-based hypochlorite chemosensors A16–A19, and perchlorate chemosensor A20 and E2a.
| λabs (nm) a |
λem (nm) b |
Φ (%) c |
Original Emission Colour | Emission Colour/Change in the Presence of Anion | L.O.D d | Mechanism of Detection | Ref. | |
|---|---|---|---|---|---|---|---|---|
| Hypochlorite (ClO − ) Sensors | ||||||||
| A16 | 250, 321 | 470 (aggr) f | 1.0 (soln) e; 33.0 (aggr) f |
Sky blue (aggr) f | Quenched | 28 nM | Boronic ester groups converted to –OH groups, then A16 further oxidised to water-soluble quinone form | [60] |
| A17 | ~340, 420 | ~595 (aggr) f | - | Strong red FL (aggr) f | Weak green | 0.47 μM | 1,1′-dicyanovinyl group converted to aldehyde group | [61] |
| A18 | 538 | 514 (aggr, +ClO−) f,h | 15.7 (+ClO−) h | - | Blue-green, turn-on | 13.2 nM | Cleavage of C=C bond into aldehyde group, detaching the indole group that causes TICT. | [62] |
| A19 | - | 469 (aggr) f | 1.1; 6.7(+ClO−) h | Blue (aggr) f; | Blue, enhanced | 75 nM | Cleavage of C=C bond carrying 2-thioxo-dihydro-pyrimidine-4,6-dione groups. | [63] |
| Perchlorate (ClO4 − ) Sensors | ||||||||
| A20 | ~375 | 650 (soln) e; 632 (aggr, +ClO4−) f,h | - | - | Red, turn-on | 0.96 μM | ClO4−-mediated aggregation | [64] |
| E2a | 396 | 580 (soln) e; 570 (aggr) f; 575 (solid) g | 14.2 (soln) e; 2.1 (aggr) f; 35.9 (solid) g | Red (soln) e | Orange | 0.38 μM | ClO4− induced self-assembly/aggregation | [65] |
a Absorption maxima; b Emission maxima; c Fluorescence quantum yield; d Limit of Detection; e (soln) denotes optical properties in solution state; f (aggr) denotes optical properties of aggregates; g (solid/film/gel) denotes optical properties in solid/film/gel state; h (+Xn+/−) denotes optical properties in the presence of ion Xn+/−. “-”: data were not reported.