Radical-mediated electrical enzyme assay for estradiol: Toward point-of-care diagnostics
Hyun-June Jang, Hyou-Arm Joung, Xiaoao Shi, Rui Ding, Justine Wagner, Erting Tang, Wen Zhuang, Byunghoon Ryu, Guanmin Chen, Kiang-Teck Jerry Yeo, Jun Huang, Junhong Chen
Applications: REEA
Reactive species: Unspecified reactive species
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Abstract: The diagnosis and prognosis of many conditions such as cardiovascular, neurodegenerative, and reproductive disorders often require repeat monitoring of small molecules, proteins, hormones, or other biomarkers with a high analytical sensitivity. We developed a radical-mediated electrical enzyme assay (REEA) in a paper-based fluidic cartridge ($0.55/test) with a handheld reader utilizing field-effect transistors to measure estradiol (E2), a key hormone in reproductive care. The system demonstrated a detection limit of 146 fg/mL, a coefficient of variation below 9.2%, and an accuracy of 0.963 across 19–4,551 pg/mL in clinical plasma samples, with results delivered in under 10 min. The REEA method presents a high-sensitivity electrochemical transducing system and can be used to detect other high-sensitivity biomarkers, including cardiac troponin and tau proteins associated with Alzheimer’s disease."
Article snippet: Additionally, anti-17β-estradiol monoclonal antibody (CD Creative Diagnostics, DMATBT-49063MH),
E2- HRP conjugate (CD Creative Diagnostics, DAGA-025B-HRP), and 17β-estradiol standard (CD Creative Diagnostics, DAGS 030) were acquired.
Figure 1. SNR as a function of AuNP-HRP-E2 conjugate concentration in testing samples