Sensing and Bio-Sensing Research (Feb 2024)
Simultaneous detection of CA-125 and mesothelin by gold nanoparticles in surface plasmon resonance
Abstract
The early-stage diagnosis and monitoring of disease evolution is still one of the most challenging tasks in the field of cancer research. Several research have been driven toward the discovery of new cancer biomarkers as well as to the development of biosensors able to detect these biomarkers with high specificity and sensitivity. Many types of cancer have been detected at an advanced stage and, in particular, epithelial ovarian cancer (EOC) has a high incidence of diagnosis in the metastatic stage. This cancer is considered as the most aggressive type of gynecological cancer with a 5-year survival and until now, no specific biomarkers have been identified. Nevertheless, some studies have indicated that mesothelin, a protein overexpressed by tumour cells in the ovary, interacts with the CA-125 biomarker present in the blood system accelerating the metastatic process. Therefore, the simultaneous presence of CA-125 and mesothelin in the blood during the evolution of EOC could be used to diagnose this disease before the metastasis. Therefore, with this motivation, this work aimed at the development of a biosensor capable of simultaneously detecting mesothelin and CA-125 at low concentrations. A biosensor based on the surface plasmon resonance imaging (SPRi) technique was developed and gold nanoparticles (AuNPs) were used in order to enhance the sensitivity. The study analysed successive injections of the biomarkers CA-125 and mesothelin, both in solution (analytical range of 9–120 nM). The limits of detection were obtained for CA-125 and mesothelin, being of 3.03 nM and 13.62 nM, respectively. The biosensor detected mesothelin at a concentration close to the cutoff point for EOC (3 nM) and was able to detect the biomarker CA-125 at 9 nM. Furthermore, the biosensor interacted preferentially and simultaneously with the biomarkers CA-125 and mesothelin incubated in fetal bovine serum. Finally, the use of AuNPs increased the sensor signal for CA-125 detection compared to its direct detection and showed greater selectivity for both biomarkers. Therefore, the biosensor has important characteristics that allow testing with real samples. In a future project, it could be applied in the research of diagnosis and prognosis of EOC.
