Endocrine Abstracts

Objective: Pollution of endocrine disrupting chemicals has become a global issue. As one of the hormonally active compounds, 17β-estradiol produces the strongest estrogenic effect when it enters the organism exogenously including food intakes, bringing potential harmfulness such as malfunction of the endocrine system. Therefore, in order to assure food safety and avoid potential risks of 17β-estradiol to humans, it is of great significance to develop rapid, sensitive and selective approaches for the detection of 17β-estradiol in food matrices.

Method: Molecular recognition elements are valuable tools for rapidly and selectively binding to target proteins. Aptamers, commonly referred to as chemical antibodies, are one such category of molecular recognition elements, exhibiting several advantages such as smaller size, stability, cost-effectiveness, easy modification, low immunogenicity, and scalability for production. As a result, aptasensors combined with diverse detection technologies offer a promising alternative for the detection of clinical biomarkers across various sample types, enabling rapid and direct analysis. A developed freezing method has proven to be remarkably simple and efficient through gold nanoparticles (AuNPs) functionalized with thiolated DNA and poly (A)-tagged DNA. When the AuNPs are coated with polymers and DNA sequences, aggregation of AuNPs becomes reversible after freezing and thawing. Building upon this freezing-directed approach, the bioprobes based on AuNPs have been successfully implemented in a variety of detection systems, including colorimetric, fluorescence, and lateral flow assays. Inspired by this, we propose and demonstrate a rapid and concise dual-mode aptasensor (named RCPA) for reliable detection of 17β-estradiol.

Result: The RCPA strategy shows ultrahigh sensitivity to 17β-estradiol determination due to high binding affinity of aptamers, with the limit of detection of 0.018 ng/ml. The total detection time of 17β-estradiol in milk or serum is less than 30 min with small sample consumption (about 50 μ L) due to the rapid magnetic separation of apt@MNP. In addition, the proposed biosensor exhibits a high specificity for 17β-estradiol quantitative detection. On the other hand, the freeze-thaw mode provides a visual and concise detection method.

Conclusion: Therefore, this work provides a promising and concise strategy to rapid and ultrasensitive detection of 17β-estradiol for broader patients and more urgent cases.

KeyWords: Aptasensor, 17β-estradiol, Detection, Gold nanoparticles