Question

Give a detailed explaination on Electrochemiluminescence, and explain a way that it may be used for biosensing applications? I really need an in depth explaination guys, so please go all out and into detail. Thanks in advance, much love xx

Answer 1

3Electrochemiluminescence

Introduction -

Electrochemiluminescence (also called as electrogenerated chemiluminescence abbreviation ECL) involves generation of species at electrode surface that then undergoes electron transfer reaction to form an excited state which emits light.

For Example

application f voltage to an electrode in presence of ECL luminophore such as Ru(bpy)_3²⁺  (bpy= 2,2'-bipyridine) results in light emission and allows detection of the emitter at a very concentration (<10^-11 M)

Traditionally, ECL was generated by annihilation where electron transfer reaction is in between an oxidized and reduces species, both are generated at the electrode by the alternate pulsing of elected potential. ECL can also be generated in a single potential step utilizing coreactant. Coreactant ECL has been used in a wide range of analytical applications including clinical diagnostic, chromatography, food and water testing. ECL also used to monitor enzymatic reactions. By employing ECL-active species as a label on biological molecules ECL has found application in immunoassay and DNA analysis. ECL based systems are highly selective and sensitive.

The first detailed studies have been done in mid-1960 after which over 1000 papers, patents, and book are published on ECL.

Principle of ECL

ECL means converting electrical energy into radiative energy. EC involves the production of reactive intermediates from the stable precursor at the surface of the electrode. These intermediate then react at a verity of condition to emit light. Ex ECL from Ru(bpy)_3²⁺ was first reported in 1972, in acetonitrile using tetrabutylammonium tetrafluoroborate as an electrolyte. ECl was generated by the alternate pulsing of electrode potential to form oxidized Ru(bpy) _3³⁺ and reduced Ru(bpy)_{3 ⁺}

Biosensing application -

ECL especially nanomaterial-based ECL is versatile and commercial developed method has attracted tremendous attention. Because of high sensitivity, ECL has vide applications in biochemistry and biosensing. ECL extensively employed for the quantitive determination of the different type of protein analyte. DNA sensing.