Dynamically controllable hot spots in DNA-derived hydrogel scaffold SERS substrate for exosome recognition using DNA self-assembly amplification

Abstract

In the context of surface-enhanced Raman scattering (SERS) applications, an effective active substrate is supposed to exhibit a high enhancement factor, long-term stability, and excellent repeatability, as well as allow target molecules to enter the hot spot area with adequate quantity and affinity. The electromagnetic field in hot spots can be drastically amplified and results in an extraordinary large signal enhancement. However, uncontrolled formation of hot spots has hampered the realization of this intention. Here, we reported an innovative SERS active substrate, named as DNA-derived dynamic hydrogel scaffold (DDHS), which is endowed with the robust electromagnetic enhancement and exceptional target affinity. Based on this integrated microfluidic chip, rationally designed DNA oligonucleotides were introduced to recognize exosome indicator-CD63, which achieved a limit of 2.63 particles μL−1. Taken together, we believed that the proposed strategy would be possible to accelerate SERS applied to trace detection of tumor biomarkers, thus offering a promising route toward screening test and early diagnostic of cancerdiseases.