Simple and Ultrasensitive Detection of Glioma-Related ctDNAs in Mice Serum by SERS-Based Catalytic Hairpin Assembly Signal Amplification Coupled with Magnetic Aggregation

Abstract

Purpose Circulating tumor DNA (ctDNA) is more representative and accurate than biopsy and is also conducive to dynamic monitoring, facilitating accurate diagnosis and prognosis of glioma. Therefore, the present study aimed to establish and validate a novel amplified method for the detection of IDH1 R132H and BRAF V600E, which were associated with the genetic diagnosis of glioma. Patients and Methods A dual-signal amplification method based on magnetic aggregation and catalytic hairpin assembly (CHA) was constructed for the simultaneous detection of ctDNAs. When target ctDNAs are present, the CHA reaction is initiated and leads to the assembly of Au-Ag nanoshuttles (Au-Ag NSs) onto magnetic beads (MBs). Further enrichment of MBs under an external magnetic field facilitated the dual-signal amplification of SERS. Results The limit of detection (LOD) for IDH1 R132H and BRAF V600E in serum was as low as 6.01 aM and 5.48 aM. The reproducibility and selectivity of the proposed SERS analysis platform was satisfactory. Finally, the platform was applied to quantify IDH1 R132H and BRAF V600E in the serum of subcutaneous-tumor‑bearing nude mice, and the results obtained by SERS were consistent with those from quantitative real-time polymerase chain reaction (qRT-PCR). Conclusion The present study showed that the dual-signal amplification method is a simple and ultrasensitive strategy for gliomas-associated ctDNAs detection, which is crucial for early diagnosis and dynamic monitoring.

Bottom‐up DNA nanostructure‐based paper as point‐of‐care diagnostic: From method to device

“…To address these issues, considerable research has been devoted to the integration of low‐cost, stable and accessible functional nucleic acids (FNAs) into paper‐based devices (Table 1). 15–20 FNAs have been used extensively as a tool for target recognition and signal amplification, with the specificity to detect single nucleotide polymorphisms (SNPs), 21 sensitivity at the aM level 22,23 and the potential for multi‐throughput detection 24 . Several recent reviews have also discussed specific aspects of FNA as a powerful detection tool, including the development of FNA‐coupled nanomaterials and devices 25–27 .…”

Responsive DNA Nanostructures for Bioanalysis and Therapy

“…Stimuli that trigger the transformation of DNA nanostructures includes external factors (such as light [21][22][23], temperature [24][25][26], or magnetic field [27][28][29]) and internal factors (such as acidity [30,31], small molecules [32][33][34], nucleic acids [35][36][37], or proteins [35,38,39]). In response to stimuli activation, the programmed DNA nanostructures would generate optical or electrical signals or release cargoes through specific conformational changes or bond breaks.…”