Amplified electrochemical detection of circular RNA in breast cancer patients using ferrocene-capped gold nanoparticle/streptavidin conjugates

Circular RNAs (circRNAs) are a class of endogenous RNAs with a closed loop structure and extensively exist in mammalian cells. Evidence show that circRNA AHNAK was closely associate with triple-negative breast cancer and may serve as new biomarker. In this work, a sandwich structure with two complementary DNA probes were designed to recognize target circRNA. Voltammetric quantification of circRNA was accomplished by the attachment of ferrocene (Fc)-capped gold nanoparticle/streptavidin conjugates to the biotinylated probe. The oxidation current of Fc was proportional to the concentration of circRNA between 0.5 pM and 10 pM with a detection limit of 0.22 pM. The feasibility of the method was demonstrated by detection of circRNA in PCR products amplified from blood of breast cancer patients and healthy donors. The sensing protocol is simple and sensitive, holds great potential for detection of circRNAs in clinical samples.

Automated summary

Circular RNAs have a closed loop structure and are extensively present in mammalian cells. Evidence suggests their potential association with triple-negative breast cancer. A sandwich structure with ferrocene-capped gold nanoparticle probes was used for sensitive detection of circRNA in clinical samples, demonstrating high potential for clinical applications.