Self-assembled poly-HRP dual signal amplification strategy for high-sensitive detection of circulating miR-142-3p in human serum

The establishment of a highly sensitive and efficient platform for detecting circulating miRNA in serum is important for disease diagnosis and prognosis. To this end, a self-assembled horseradish peroxidase (HRP)-based polymer (poly-HRP) dual signal amplification strategy, via skillful combination of functionalized magnetic nanoparticles as the capture nanoprobes and the poly-HRP as signal amplification probes, has been developed for highl-sensitive and accurate detection of circulating miR-142-3p in human serum. Just by mixing building blocks together at one time, the poly-HRP used for dual signal amplification can be engineered by only one-step assembly. As the poly-HRP can be directly prepared ahead, avoiding chain amplification reaction in the detection process, the assay can be rapidly accomplished in about one hour. The measured limit-of-detection (LOD) is down to 100 fM. Standard miR-142-3p spiked in human serum is measured with ideal recovery rates ranging from 97.46% to 115.90%. More importantly, this method was validated to be applicable to direct detection of miR-142-3p in serums, and the results suggested that the miR-142-3p levels of serum samples obtained from T-cell acute lymphoblastic leukemia children (n = 25) are significantly higher than those from healthy control groups (n = 25) ( P  < 0.01). To conclude, the ingenious combination of functionalized magnetic nanoparticles and the poly-HRP presented in this work brings forth a rapid, convenient, yet simple, sensitive, and specific biosensing method that can potentially be applied for clinical diagnosis.