Ultrasensitive electrochemical biosensor based on triple signal amplification strategy for detection of serum cf-miR-181b: A possible biomarker related to osteosarcoma’s early diagnosis and chemotherapy monitoring

Abstract

Osteosarcoma is one of the most common primary malignant bone tumors, however, the current diagnostic methods based on tissue biopsy suffers from invasive operation, high heterogeneity and non-early diagnosis. Herein, we proposed a new liquid biopsy method using triple signal amplification-based electrochemical biosensor (E-sensor) in detection of serum cf-miR-181b closely related to osteosarcoma. The E-sensor adopted an enzyme-linked DNA magnetic microbead (MMB), in which the miR-181b-triggered ligase chain reaction products were immobilized onto the surface of MMB followed by the attraction of horseradish peroxidase, to produce a catalytic current on the electrode surface. The E-sensor could detect miR-181b as low as 6.70 aM with a single-base resolution. Finally, the E-sensor was applied to detect serum cf-miR-181b in different individuals, which exhibited excellent performance in discriminating serum miR-181b between control group (healthy people/non-osteosarcoma patients) and osteosarcoma patients. Also, this assay could be used to distinguish the osteosarcoma patients before and after effective chemotherapy. In parallel, all results were in good agreement with that obtained by qRT-PCR. Therefore, the proposed E-sensor, due to its low cost, easy miniaturization and generalization, holds a huge application potential in the early auxiliary diagnosis and therapeutic monitoring of osteosarcoma and is of great value in clinical translation.