Multistage nucleic acid amplification induced nano-aggregation for 3D hotspots-improved SERS detection of circulating miRNAs

Abstract

Circulating miRNAs in the blood can regulate disease development and thus indicate disease states via their various expression levels. For these reasons, circulating miRNAs constitute useful biomarkers, and an approach to the accurate detection of circulating miRNAs is attractive in the diagnosis and treatment of diseases. However, methods for clinical detecting of circulating miRNA that take both sensitivity and practicality into account are still needed. Therefore, we aimed herein to solve some inherent problems in the actual detection using a robust surface-enhanced Raman scattering (SERS) platform with integrated nucleic acid amplification and nanoparticle aggregation to construct 3D hotspots for improving performance of analyzing circulating miRNAs. After target recognition and initial signal amplification by DNAzyme, we observed that release triggered an open hairpin DNA on gold nanoparticles (AuNPs), which then promote AuNP aggregation, causing the accumulation of a large number of hotspots in three-dimention. The SERS biosensor achieved a better performance than the sandwich-type separation detection, with a low detection limit (0.37 fM) and a broad linear range (1 fM–10 nM) in liquids. This SERS platform can be used as a powerful tool for the detection of circulating miRNAs, and it can be used to improve the sensitivity and accuracy of various clinical-disease diagnoses. Graphical Abstract

Dual-clamped one-pot SERS-based biosensors for rapid and sensitive detection of SARS-CoV-2 using portable Raman spectrometer

“…The SEM and TEM images of Ab-AgNPs-4MBA complex (SERS nanotags), as shown in Fig. 1 C-D, exhibited slight aggregation compared to AgNPs, which could serve as more hot spots for strengthening the SERS response [36] , [46] . The successful conjugation of AgNPs with antibody and Raman reporter (4MBA) was monitored using UV–vis spectroscopy, SERS signals, and zeta potential measurements.…”

“…Though these SERS substrates displayed high sensitivity, the reproducibility of SERS signals has been mostly poor due to the non-uniform distribution of hot junctions over the plasmonic substrates. On the other hand, the detection time is usually long due to tedious reaction or washing processes (centrifugation of sample or rinsing of substrates to remove unbound molecules) for highly sensitive detection [30] , [36] , and cost-effectiveness is an issue in many of the above-mentioned SERS substrates. Keeping these limitations in mind, in this study, we considered compact disk technology as an alternate choice to fabricate a cost-effective and stable substrate for SERS based biosensors.…”

Liquid biopsy techniques and lung cancer: diagnosis, monitoring and evaluation

“…However, it is crucial to emphasize the efficacy of individual miRNAs in lung cancer diagnosis to strike a balance between effectiveness and cost. While specific diagnostic models containing multiple biomarkers exhibit good predictive diagnostic efficacy, their low reproducibility and complex composition pose substantial challenges for the practical application of miRNAs in the early diagnosis of lung cancer [ 133 ]. Advancements in sequencing technology have led to the identification of various lncRNAs and circRNAs that exhibit differential expression in lung cancer blood and tissue.…”

Lectin-conjugated nanotags with high SERS stability: selective probes for glycans

“…The presence of paracetamol led to aggregation of AuNPs, where SERS intensity of paracetamol was proportional to the concentration of paracetamol. In another work, Sun et al 29 have used labeled SERS nanotags for quantification of circulating miRNAs. In the presence of target miRNA, the DNA-functionalized SERS nanotags aggregated and formed 3D hotspots, where the SERS intensity was proportional to the concentration of miRNA in the range of 1 fM-10 nM.…”