Acridine ester, as an important chemiluminescence marker, has a wide range of applications in biological detection, medical diagnosis and other fields. However, its stability in aqueous solution, especially its hydrolysis characteristics, is one of the key factors affecting its application effectiveness. This article will provide a detailed exploration of the hydrolysis mechanism, influencing factors, and stability improvement measures of acridine esters.
1、 The hydrolysis mechanism of acridine ester
The hydrolysis process of acridine ester in aqueous solution is a complex chemical reaction. When the pH value in the solution exceeds a certain range (especially under alkaline conditions), the ester bonds in the acridine ester molecules are easily attacked by OH - ions, generating a pseudo base. Subsequently, under the continued action of OH - ions, the ester bond of the pseudo base is broken, ultimately resulting in the formation of N-methylacridone. This hydrolysis process is a non luminescent dark reaction process, which can lead to a decrease in the stability of acridine ester, thereby affecting its luminescence effect and detection sensitivity.
2、 Factors affecting the hydrolysis of acridine esters
PH value: pH value is one of the key factors affecting the hydrolysis of acridine esters. When the pH value of the solution is less than 4.8, the photo quantum yield of acridine ester and its protein conjugate does not decrease after being stored at room temperature for 4 weeks; Freeze dried products can be stored for more than one year at -20 ℃. However, when the pH value is greater than 4.8, especially in alkaline solutions, the stability of acridine esters will significantly decrease, and the degree of hydrolysis will increase with the increase of pH.
Temperature: Temperature is also an important factor affecting the hydrolysis of acridine esters. As the temperature increases, the hydrolysis rate of acridine ester will accelerate and its stability will decrease. Therefore, it is necessary to control the appropriate temperature during storage and use to ensure the stability of acridine esters.
Substituents: The type of substituent attached to the acridine ring, phenolic ring, or benzenesulfonyl ring can also affect the stability of acridine esters. Acridine esters or acridine sulfonamides with methyl or other substituents have increased thermal stability due to their high steric hindrance; When there are electron withdrawing groups attached, the stability decreases due to the favorable nucleophilic substitution reaction.
3、 Measures to improve the stability of acridine esters
Control pH value: Acridine esters exhibit high stability in acidic environments (pH<4.8). Therefore, during storage and use, it is important to ensure that the pH value of the solution is within the acidic range to avoid stability degradation caused by alkaline environments.
Use appropriate solvents: Acridine esters have good solubility in non protonic solvents such as DMF and anhydrous DMSO. Choosing these solvents can improve their stability and solubility, facilitating subsequent experiments.
Avoid oxidative environment: Oxidative environment can damage the structure of acridine ester, leading to a decrease or even loss of fluorescence signal. Therefore, during storage and use, contact with oxidants should be avoided as much as possible, and the environment should be kept dry and sealed.
Optimization of diluent formula: Using a diluent containing multiple components such as Trisbase, polyethylene glycol 6000, and sodium dodecyl sulfate can improve the stability of acridine ester antigen antibody complexes and reduce non-specific reactions, providing good blocking and protective properties for antibodies.
Avoid light storage: Luminescent markers may decompose under light conditions, affecting their fluorescence effect. Therefore, acridine esters should be stored in a dark environment to maintain their good fluorescence properties.
In summary, the hydrolysis characteristics of acridine esters are one of the important factors affecting their application effectiveness. By controlling the pH value, temperature, selecting appropriate substituents, and adding stabilizers, the stability of acridine esters can be effectively improved, thereby ensuring their application effectiveness in fields such as biological detection and medical diagnosis.
Hubei Xindesheng Material Technology Co., Ltd. specializes in the production of chemiluminescence reagents. Currently, in addition to the acridine ester series products, we also sell powder reagents such as luminol, isoluminol, and luminol monosodium salt. Desheng has a strong research team and R&D capabilities, and can provide customized product services according to customer needs. If interested, please click on the official website to learn more details!
