Classification and application of chemiluminescence immunoassay

 In recent years, chemiluminescence immunoassay has been increasingly favored by people because of its high sensitivity, strong specificity, wide application range, simple equipment and wide linear range. It has been widely used in life sciences, clinical medicine, environment and food, drugs and other fields. Chemiluminescence immunoassay is a combination of highly sensitive chemiluminescence detection with highly specific immunoassays for the detection of various antigens, haptens, antibodies, hormones, enzymes, fatty acids, vitamins and drugs.

Chemiluminescence immunoassay

Chemiluminescence analysis is an analytical method for determining the content of a substance based on the intensity of the radiant light generated by the chemical reaction. Chemiluminescence immunoassay combines a chemiluminescence system with an immunological reaction, and binds an antibody or antigen with a chemiluminescence-related substance, reacts with the antigen or antibody to be tested, and then separates the free chemiluminescent label and adds it to the chemiluminescence system. Other related substances produce chemiluminescence for quantitative or qualitative detection of antigens or antibodies. The four most widely used markers in chemiluminescent immunoassays are luminol, isoluminol and its derivatives, acridinium ester derivatives, peroxidase and alkaline phosphatase.

Classification of chemiluminescence immunoassays

According to the difference between the labeling and luminescence principle used in chemiluminescence, it can be generally divided into three categories: direct chemiluminescence immunoassay, enzymatic chemiluminescence immunoassay and electrochemiluminescence immunoassay. Unlike the former two, electrochemiluminescence generates an optical signal by electrochemical reaction of an electrochemical illuminant on the surface of an electro-actuator electrode, and a co-reactant is often required to improve luminous efficiency, such as tripropylamine (TPA) is used as an electron donor co-reactant of Rb(bpy)₃]²⁺). The commonly used luminescent systems are: acridinium esters, luminols, terpyridines, peroxy oxalates (TCPO, DNPO) and strong oxidants potassium permanganate, Ce(SO₄)₂, etc. Some luminescent agents react slowly with oxidants, and also require the action of catalysts and enhancers to improve luminescence intensity and stability.

Application of chemiluminescence immunoassay

The chemiluminescence immunoassay method has both high sensitivity for chemiluminescence analysis and high specificity for immune response. It has broad application and development prospects in the fields of clinical diagnosis, food safety and environmental monitoring.

1. Rapid chemiluminescence immunoassay method

Traditional immunoassay methods often take hours to complete, and long incubation times also cause adsorption of immunological reagents on the inner wall of the tube, increasing signal crossover between different assays, thus limiting sample throughput and immunoassay methods. In order to overcome these shortcomings and achieve high throughput of immunoassay, the mass transfer rate of biological macromolecules such as antigens and antibodies can be accelerated by external field driving or effective mixing strategy, or the temperature of the reaction system can be increased to accelerate the kinetics of the immune reaction to achieve rapid immunoassay.

2. Multi-component chemiluminescence immunoassay method

Simultaneous realization of multi-component detection in a single analysis process has the outstanding advantages of high throughput, short time required, low sample consumption, and low analysis cost. It is a long-term goal of immunoassay and a hot research spot on immunoassay in recent years.

3. Highly sensitive chemiluminescence immunoassay method

In the actual detection, the sensitivity and specificity of the existing detection methods are not ideal, and the highly sensitive and highly selective detection methods are increasingly showing their importance. The development of nanotechnology provides an opportunity for the development of highly sensitive chemiluminescence immunoassay methods. Nanoparticles have been widely used in biomarker analysis. A variety of signal amplification methods have been used for the construction of highly sensitive immunoassays.

Edited by Suzhou Yacoo Science Co., Ltd.