Direct vs Enzyme catalyzed Chemiluminescence Empowering Medical Diagnosis and Biological Detection

In modern fields such as biological detection and medical diagnosis, chemiluminescence technology plays an indispensable role due to its high sensitivity and specificity. Chemiluminescence refers to the phenomenon in which a substance absorbs the energy released during a chemical reaction and emits light when it returns from an excited state to its ground state. According to whether the reaction requires enzyme catalysis, it can be divided into two categories: direct chemiluminescence and enzyme catalyzed chemiluminescence. Next, we will take acridine ester and luminol as examples to explore in depth the principles and characteristics of these two types of chemiluminescence.

1, Direct chemiluminescence: taking acridine ester reaction as an example

The core feature of direct chemiluminescence is that the luminescent product directly participates in chemical reactions and can complete the luminescence process without the assistance of other catalysts. The reaction between acridine ester and hydrogen peroxide is a representative example of direct chemiluminescence.

Acridine esters are a type of compound with a special chemical structure, which contains an acridine ring in its molecular structure, laying the foundation for subsequent luminescence processes. When acridine ester meets hydrogen peroxide under suitable reaction conditions, a chemical reaction occurs rapidly. In this reaction process, two substances interact with each other to generate a new derivative of acridine ester. It is worth noting that this chemical reaction releases a certain amount of energy, which is precisely absorbed by the newly generated molecules of acridine ester derivatives.

After absorbing energy, the electronic state of acridine ester derivative molecules changes, transitioning from a lower energy ground state to a higher energy excited state. However, molecules in an excited state are not stable and will spontaneously return to a lower energy, more stable ground state in a very short period of time. During the process of molecules returning from the excited state to the ground state, excess energy is released in the form of light radiation, resulting in the observed chemiluminescence phenomenon. Throughout the entire process, the generated acridine ester derivatives are both reaction products and luminescent materials that emit light radiation, which fits the definition of direct chemiluminescence where luminescent products directly participate in the reaction. This luminescence method has the advantages of fast reaction speed and stable luminescence intensity, and has wide applications in fields such as immunoassay.

2, Enzyme catalyzed chemiluminescence: taking the luminol reaction as an example

Unlike direct chemiluminescence, enzymatic chemiluminescence requires the catalysis of specific enzymes to proceed smoothly and produce light radiation. The luminescence reaction of luminol is a typical enzymatic chemiluminescence process.

Luminol itself is a stable chemical substance that reacts very slowly with hydrogen peroxide in the absence of a catalyst, making it almost impossible to observe significant light radiation phenomena. And when horseradish peroxidase (HRP) or plant peroxidase (POD) is added, the entire reaction process undergoes fundamental changes. HRP or POD as catalysts can significantly reduce the activation energy of the reaction between luminol and hydrogen peroxide, accelerating the progress of the reaction.

Under the catalytic action of enzymes, luminol undergoes an oxidation-reduction reaction with hydrogen peroxide, producing an intermediate product in an excited state. The intermediate products of this excited state are also unstable and quickly transition back to the ground state from the excited state, releasing energy in the process and generating light radiation. In the luminescent reaction of luminol, enzymes (HRP or POD) do not directly participate in the final process of light radiation. Their main role is to catalyze the occurrence of chemical reactions and create conditions for the luminescent process. It is precisely because of the crucial characteristic of enzyme catalysis that the luminescent reaction of luminol is classified as enzymatic chemiluminescence. Enzymatic chemiluminescence has the characteristics of extremely high sensitivity and the ability to adjust luminescence intensity by controlling the amount of enzyme. It plays an important role in trace substance detection, biomolecule labeling, and other fields.

3, Comparison and application value of two types of chemiluminescence

Although there are differences in the luminescence principles between direct chemiluminescence (such as acridine ester reaction) and enzymatic chemiluminescence (such as luminol reaction), they are both based on the core mechanism of chemical reaction releasing energy and converting it into light radiation. Direct chemiluminescence does not require enzyme involvement, and the reaction process is relatively simple and fast, making it suitable for scenarios that require high detection speed; Enzymatic chemiluminescence, with the catalytic effect of enzymes, greatly improves the sensitivity of the reaction and is more suitable for the detection of trace substances.

In practical applications, researchers will choose the appropriate chemiluminescence type according to different detection requirements. For example, in clinical diagnosis, direct chemiluminescence can be used to quickly detect indicators such as viral antigens, providing timely basis for early diagnosis of diseases; Enzyme catalyzed chemiluminescence can be used to detect trace biomolecules such as tumor markers, assisting in early screening and monitoring of cancer. With the continuous development of technology, two types of chemiluminescence technologies are also constantly optimized and innovated, providing more efficient and accurate solutions for detection work in various fields.

Hubei Xindesheng Materials Co., Ltd. has many years of experience in the production and research and development of chemiluminescence reagents. A lot of effort has been invested in the research and development of acridine esters and luminol. At present, the company's products have been sold to more than 100 countries, and most of them have received positive reviews and repurchases. The product quality is excellent, and prices are discounted. If you are interested in learning more, you can call us for consultation. Desheng welcomes your call.