Annihilation ECL

There are two dominant pathways through which ECL can be obtained annihilation pathway and co-reactant pathway. Although most of the ECL applications are based on the co-reactant pathway, the early ECL emission originated from annihilation ECL. 

In the annihilation pathway, the reduced and oxidized species are both generated in the vicinity of the electrode surface by alternate pulsing of the electrode potential. The corresponding process is outlined in the Eqn (1-4). The annihilation ECL can also be achieved in the mixed systems . The ECL is achieved via cross-reactions between the radical ions of the different species. 

For the efficient generation of annihilation ECL, three conditions should be met as follows (1) sufficient energy in the electron transfer reaction to produce the excited state for ECL emission, (2) stable radical ions of the precursor molecules in the electrolyte, and (3) good PL efficiency of a product of the electron transfer reaction. 

Annihilation ECL involves electrOTi transfer reactions between an oxidized and a reduced species, both of which are generated at an electrode by... 

Figure 13.7 (a) Commonly used cell for annihilation ECL study, (b) which can be fabricated from ACE glass internal threaded connectors, (c) Teflon or PTFE plugs, (for colour version see colour section at the end of the book). 

Plate 23 (a) Commonly used cell for annihilation ECL study, (b) which can be fabricated from... 

---