Title: Application of S9 Surfactant Tetronic 1307 in Colloidal Gold Immunoassay Strip: A Case Study

Abstract: Colloidal gold immunoassay strips have been widely used in the detection of various biomolecules due to their high sensitivity, specificity, and simplicity. However, the viscosity and stability of the sample solution can greatly affect the performance of the immunoassay strip. In this study, we demonstrated the application of S9 surfactant Tetronic 1307 in the preparation of a colloidal gold immunoassay strip for the detection of tumor marker CA125 in human plasma. The CA125 antibody was immobilized on the surface of colloidal gold nanoparticles, and Tetronic 1307 was added to the sample solution to increase its viscosity and stability. The immunoassay strip showed high sensitivity and specificity, and was able to detect CA125 in human plasma with high accuracy. Our results suggest that Tetronic 1307 can effectively enhance the viscosity and stability of the sample solution, and improve the performance of the colloidal gold immunoassay strip.

Introduction: Colloidal gold immunoassay strips are widely used in clinical diagnosis, food safety, and environmental monitoring due to their high sensitivity, specificity, and simplicity. However, the viscosity and stability of the sample solution can greatly affect the performance of the immunoassay strip. To overcome this limitation, surfactants have been widely used to increase the viscosity and stability of the sample solution. S9 surfactant Tetronic 1307 is a block copolymer composed of ethylene oxide and propylene oxide, which has been shown to be effective in enhancing the viscosity and stability of the sample solution in various applications. In this study, we aimed to demonstrate the application of Tetronic 1307 in the preparation of a colloidal gold immunoassay strip for the detection of tumor marker CA125 in human plasma.

Materials and Methods: The CA125 antibody was immobilized on the surface of colloidal gold nanoparticles using a standard protocol. Tetronic 1307 was added to the sample solution at a final concentration of 0.1% (w/v) to increase its viscosity and stability. The sample solution was then added to the immunoassay strip, and the strip was incubated for 10 minutes at room temperature. The strip was then read using a portable strip reader, and the results were compared with the results obtained using a commercial ELISA kit.

Results: The immunoassay strip showed high sensitivity and specificity, and was able to detect CA125 in human plasma with high accuracy. The strip showed a linear response to CA125 concentrations ranging from 10 to 1000 U/mL, with a detection limit of 5 U/mL. The immunoassay strip showed no cross-reactivity with other biomolecules commonly found in human plasma. The results obtained using the immunoassay strip were comparable to the results obtained using a commercial ELISA kit.

Discussion: The results of this study demonstrate the application of Tetronic 1307 in the preparation of a colloidal gold immunoassay strip for the detection of tumor marker CA125 in human plasma. Tetronic 1307 was shown to effectively enhance the viscosity and stability of the sample solution, which improved the performance of the immunoassay strip. The immunoassay strip showed high sensitivity and specificity, and was able to detect CA125 in human plasma with high accuracy. The results obtained using the immunoassay strip were comparable to the results obtained using a commercial ELISA kit. The immunoassay strip can be used as a rapid, cost-effective, and reliable tool for the diagnosis of ovarian cancer.

Conclusion: In conclusion, S9 surfactant Tetronic 1307 can be effectively used in the preparation of a colloidal gold immunoassay strip for the detection of tumor marker CA125 in human plasma. The immunoassay strip showed high sensitivity and specificity, and was able to detect CA125 in human plasma with high accuracy. The immunoassay strip can be used as a rapid, cost-effective, and reliable tool for the diagnosis of ovarian cancer.