The key difference between chemiluminescence and electrochemiluminescence is that chemiluminescence is the emission of radiation or light during a chemical reaction while electrochemiluminescence is a kind of chemiluminescence which occurs as a result of an electrochemical reaction happening in a solution.
Luminescence is the spontaneous emission of light or radiation by a molecule or an atom when it comes to the ground state of energy from the excited state. It is not a result of heating. It can occur when the excitation source absorbs energy from the light, chemical reaction or from the biologically catalyzed reaction. Based on that, luminescence can be photoluminescence, chemiluminescence or bioluminescence. Chemiluminescence is the emission of electromagnetic radiation such as ultraviolet, visible, or infrared during the chemical reaction. Electroluminescence is a kind of chemiluminescence. It occurs due to an electrochemical reaction happening in a solution.
CONTENTS
1. Overview and Key Difference
2. What is Chemiluminescence
3. What is Electrochemiluminescence
4. Similarities Between Chemiluminescence and Electrochemiluminescence
5. Side by Side Comparison – Chemiluminescence vs Electrochemiluminescence in Tabular Form
6. Summary
What is Chemiluminescence?
Chemiluminescence is the emission of light during a chemical reaction. As a result of the chemical reaction, one of the reaction products goes into an excited state and returns into the ground state of energy by emitting radiation such as ultraviolet, visible or infrared. One of the standard examples of chemiluminescence is the luminal test. In this test, blood is indicated by luminescence due to the contact with iron in hemoglobin.
Figure 01: Chemiluminescence
Generally, the chemical reaction must be exothermic in order to form an electronically excited state. In aqueous systems, chemiluminescence occurs mainly by redox reactions. There are many applications of chemiluminescence. In forensic studies, chemiluminescence is useful in solving crimes. When determining small amounts of impurities or poisons in the air, analyzing inorganic species and organic species in solutions, detecting and assaying biomolecules during ELISA and Western blotting, sequencing DNA using pyrosequencing, lighting objects, lighting children toys, etc. chemiluminescence is applied.
What is Electrochemiluminescence?
Electrochemiluminescence is the emission of luminescence during an electrochemical reaction. It is a type of chemiluminescence. In other words, electroluminescence is the chemiluminescence induced by an electrochemical stimulus. These luminescent signals arise due to the conversion of electrochemical energy into radioactive energy through an electrochemical reaction. Excited-state products are generated as a result of an electrochemical reaction.
Figure 02: Electrochemiluminescence
Electrochemiluminescence process does not require expensive instrumentation. There is also a smaller likelihood of interference in this process. Moreover, electrochemiluminescence is confined to the surface of the electrode or its close vicinity. Despite these advantages, frequent fouling of the electrodes is one of the major disadvantages of this process.
Generally, electroluminescence occurs especially when metal chelates undergo a series of chemical reactions at an electrode surface. There are several applications of electrochemiluminescence. During DNA hybridization, electrochemiluminescent labels are specially used since they are highly sensitive, simple and versatile.
What are the Similarities Between Chemiluminescence and Electrochemiluminescence?
- Electroluminescence is a kind of chemiluminescence.
- In both cases, spontaneous emission of light takes place.
- There are different applications of electroluminescence and chemiluminescence.
- Both chemiluminescence and electroluminescence take place due to oxidation and reduction reactions.
What is the Difference Between Chemiluminescence and Electrochemiluminescence?
Chemiluminescence is the emission of light as a result of a chemical reaction. Meanwhile, electrochemiluminescence is the emission of light due to an electrochemical reaction occurring at an electrode surface. So, the key difference between chemiluminescence and electrochemiluminescence is that the chemiluminescence is a result of a chemical reaction. But, electrochemiluminescence is a result of an electrochemical stimulus. Moreover, electrochemiluminescence takes place at an electrode surface while chemiluminescence does not.
Below tabulation shows a detailed comparison of the difference between chemiluminescence and electrochemiluminescence.
Summary – Chemiluminescence vs Electrochemiluminescence
Chemiluminescence is the emission of light during a chemical reaction. Electrochemiluminescence is a kind of luminescence produced by electrode reactions. It is also known as electrogenerated chemiluminescence. So, this is the key difference between chemiluminescence and electrochemiluminescence. Both phenomena take place due to the excited products falling into ground energy state from their excited state. Moreover, they have many applications in different fields.
Reference:
1. Fereja, Tadesse Haile et al. “A Recent Review On Chemiluminescence Reaction, Principle And Application On Pharmaceutical Analysis”. ISRN Spectroscopy, vol 2013, 2013, pp. 1-12. Hindawi Limited, doi:10.1155/2013/230858.
2. “Electrochemiluminescence – An Overview | Sciencedirect Topics”. Sciencedirect.Com, 2020, Available here.
Image Courtesy:
1. “Chemiluminescence” By Tavo Romann – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Heterogeneous ECL mechanism” By G.Valenti – Own work (CC BY-SA 4.0) via Commons Wikimedia