Materials for Electrochemiluminescence: TADF, Hydrogen‐Bonding, and Aggregation‐ and Crystallization‐Induced Emission Luminophores

Abstract

Electrochemiluminescence (ECL) is a rapidly growing discipline with many analytical applications from immunoassays to single‐molecule detection. At the forefront of ECL research is materials chemistry, which looks at engineering new materials and compounds exhibiting enhanced ECL efficiencies compared to conventional fluorescent materials. In this review, we summarize recent molecular design strategies that lead to high efficiency ECL. In particular, we feature recent advances in the use of thermally activated delayed fluorescence (TADF) emitters to produce enhanced electrochemiluminescence. We also document how hydrogen bonding, aggregation, and crystallization can each be recruited in the design of materials showing enhanced electrochemiluminescence.

Multiquenching-Based Aggregation-Induced Electrochemiluminescence Sensing for Highly Sensitive Detection of the SARS-CoV-2 N Protein

“…Aggregation-induced emission (AIE) recently has been explored to induce fluorescence emission enhancement of chromophores in an aggregate state by inhibiting the vibration and rotation of template molecules . Aggregation-induced ECL (AIECL), the combination of ECL and AIE, has gained considerable attention in wide research fields . The most simple way for AIECL luminophore preparation is the immobilization or encapsulation of AIE active groups into different substrates with regular and tightly arranged structures, such as the SiO 2 nanostructure and metal–organic frameworks (MOFs). , Gu synthesized an ECL nanoprobe that exhibited strong and stable emission by incorporating AIE ligands into Zr-based MOFs, which achieved the sensitive detection of adenosine triphosphate .…”

Thermally Activated Delayed Fluorescent Polymer Dots for Electrochemiluminescent Sensing of Cu2+ Ions

“…Although various ECL emitters have been developed, − the recent strategies to develop purely organic ECL emitters are appealing . Purely organic ECL emitters featuring the thermally activated delayed fluorescence (TADF) mechanism are groundbreaking as they overcome the inherent limitation of dark triplet exciton spin-forbidden transitions of reported fluorescent organic ECL emitters. − Triplet excitons account for ∼75% of the electrochemically generated excitons.…”

Crystallization-induced emission from F-doped carbon dots

“…21,22 However, as electron acceptors, hydrogen bonding moieties often affect excited-state electrons, affecting efficiency. 23…”