Highly Sensitive Detection of Hormone Estradiol E2 Using Surface-Enhanced Raman Scattering Based Immunoassays for the Clinical Diagnosis of Precocious Puberty

The hormone estradiol (17 beta-estradiol, E2) plays an important role in sexual development and serves as an important diagnostic biomarker of various clinical conditions. Particularly, the serum E2 concentration is very low (<10 pg/mL) in prepubertal girls. Accordingly, many efforts to develop a sensitive method of detection and quantification of E2 in human serum have been made. Nonetheless, current clinical detection methods are insufficient for accurate assessment of E2 at low concentrations (<10 pg/mL). Thus, there is an urgent need for new technologies with efficient and sensitive detection of E2 for use in routine clinical diagnostics. In this study, we introduce a new E2 assay technique using a surface-enhanced Raman scattering (SERS)-based detection method. The SERS-based assay was performed with 30, blood samples to assess its clinical feasibility, and the results were compared with data obtained using the ARCHITECT, chemiluminescence immunoassay. Whereas the commercial assay system was unable to quantify serum levels of E2 lower than 10 pg/mL, the limit of detection of E2 using the novel SERS-based assay described in this study was 0.65 pg/mL. Thus, the proposed SERS-based assay has a strong potential to be a valuable tool in the early diagnosis of precocious puberty due to its excellent analytical sensitivity.