Aromaticity-Enhanced pH-Responsive Electrochemiluminescence of Cyclopentadienols

Abstract

Due to significantly tackling the problems of aggregation-caused quenching and water insolubility, aggregationinduced emission electrochemiluminescence (AIE-ECL) has emerged as a research highlight in aqueous detection and sensing. Herein, we reported a series of cyclopentadienols featuring excellent AIE-ECL properties on the basis of an enhanced aromaticity strategy. In detail, substituents profoundly determined ECL emission by affecting the characteristic absorption peak intensity ratio in UV−vis spectra and lowest unoccupied molecular orbital (LUMO)−highest occupied molecular orbital (HOMO) energies. It was found that 1,2,3,4,5-pentafluorophenyl cyclopentadienol (PFCD) containing an electron-withdrawing fluorine substituent, the maximum R/B band ratio, and a smaller LUMO−HOMO band gap demonstrated the best ECL performance. Meanwhile, such an AIE-ECL system displayed a wide response range toward pH (4−12) with a good linear relationship. Our research not only enriched polycyclic aromatic hydrocarbon-based AIE-ECL systems but also established an efficient pH sensor in the aqueous phase.

Rigid Enhanced Electrochemiluminescence of 1,2,3-Triaryl Indenes as an Ultrasensitive Sensor for D2O in H2O

“…The energy would be mainly released in the form of ECL emission, thereby improving the ECL efficiency. Different from the reported AIE-ECL systems, − indene could also feature strong ECL emissions at a low water content. This might be beneficial for the contribution of the rigid structure to luminescence.…”

“…23−28 Since De Cola and co-workers first reported the pioneering work on the AIE-ECL of platinum complexes in 2017, 23 various luminescent substances with AIE-ECL have been developed, such as metal organic complexed, 23 carbon or polymer dots, 24−26 and AIE-active organic molecules. 27,28 In addition, these AIE-ECL systems were successfully been applied in the field of chemical detection and sensing, such as chloramphenicol sensors, methyltransferase detection, micro-RNA analysis, and so on. Despite all this, the reported AIE-ECL systems always shows low luminous efficiencies, which seriously limits their further application.…”

“…Thus, ECL plays a major role in the fields of chemical detection, immunoassays, and food and water inspection. − Meanwhile, in the past few years, some novel ECL concepts have already emerged. Among them, aggregation-induced ECL (AIE-ECL) has received widespread attention because it contributes to tackling the aggregation-causing quenching (ACQ) observed in organic emitters. − Since De Cola and co-workers first reported the pioneering work on the AIE-ECL of platinum complexes in 2017, various luminescent substances with AIE-ECL have been developed, such as metal organic complexed, carbon or polymer dots, − and AIE-active organic molecules. , In addition, these AIE-ECL systems were successfully been applied in the field of chemical detection and sensing, such as chloramphenicol sensors, methyltransferase detection, micro-RNA analysis, and so on. Despite all this, the reported AIE-ECL systems always shows low luminous efficiencies, which seriously limits their further application.…”

Studies on Annihilation and Coreactant Electrochemiluminescence of Thermally Activated Delayed Fluorescent Molecules in Organic Medium

“…Nowadays, alongside such demands, a great deal of attention is focusing on developing advanced organic ECL luminophores [ 10 , 11 , 12 , 13 , 14 , 15 ]. Especially, two peculiar strategies have been launched with great developing potential [ 16 ], that is: (i) organic aggregation-induced ECL (AIECL) [ 17 ] and (ii) thermally activated delayed fluorescent ECL (TADF-ECL) [ 18 , 19 ], respectively.…”

“…For instance, a series of organic AIECL systems were developed, e.g., tetraphenylethylene (TPE)-based nanocrystals or polymer dots [ 17 , 24 ], carbon dots [ 23 ], silole or triphenylporphyrin-based compounds [ 10 , 22 ]. Most of them showed excellent ECL stabilities and satisfactory Φ ECL and even were applied in various biosensing applications with satisfactory effects [ 14 , 15 ]. As for the topic of TADF-ECL [ 18 , 19 ], it is significant in that such a strategy is characteristic of all-exciton-harvesting for ECL emission.…”