SPRi Biosensor Analysis Of Non-small Cell Lung Cancer Exosomal MiRNA Based On Metal Nanomaterials And DNA Tetrahedral Framework

Lung cancer is the malignant tumor with the highest incidence and mortality in China,while non-small cell lung cancer(NSCLC)is the most common type of lung cancer.NSCLC patients secrete tumor-related exosomes into the human circulatory system.This vesicle structure contains a large amount of RNA,DNA,protein,lipids,carries a lot of biological information,it can regulate cell migration and physiological functions.Among them,miRNAs have great clinical value in the diagnosis of early lung cancer.In order to accurately diagnose early NSCLC,it is essential to establish a new method to detecting multiplex exosomal miRNAs simultaneous.Herein,a surface plasmon resonance imaging(SPRi)-based biosensor was developed for simultaneous detection of multiplex NSCLC-associated exosomal miRNAs in a clinical sample using Au-on-Ag heterostructure and DNA tetrahedral framework(DTF).Exosomal miRNAs are captured by various DTF probes immobilized on the gold array chip.Subsequently,single-stranded DNA(ssDNA)functionalized silver nanocube(Ag NC)hybridizes with the captured exosomal miRNAs and then the ssDNA-coated Au nanoparticles(AuNP)assembled on the surface of Ag NC,forming Auon-Ag heterostructures as essential labels to realize amplified SPR response.With the aid of DNA programmed Au-on-Ag heterostructure and DTF,the SPRi-based biosensor exhibits wide detection range from 2 f M to 20 n M,ultralow limit of detection of 1.68 f M,enhanced capture efficiency,and improved antifouling capability.Furthermore,the biosensor enables accurate discrimination of NSCLC patients based on detection results of exosomal miRNAs.Overall,this developed biosensor is a promising tool for multiplex exosomal miRNAs detection,providing a new possibility for early diagnosis of NSCLC.