Au@Ag core-shell nanoparticles for microRNA-21 determination based on duplex-specific nuclease signal amplification and surface-enhanced Raman scattering.

A novel surface-enhanced Raman scattering (SERS) analysis strategy has been designed combining Au@DTNB@Ag core-shell nanoparticles (DTNB attachment on gold nanoparticles, then encapsulated in Ag shell nanoparticles named as ADANPs) and duplex-specific nuclease signal amplification (DSNSA) platform. Firstly, ADANPs and magnetic substrate of FeO nanoparticles were covalently attached to the 3'- and 5'- end of capture probe (CP) targeting miRNA-21. Upon the addition of target miRNA-21, these heteroduplexes were specifically cleaved by DSN and resulted in ADANPs that were released from the surface of FeO nanoparticles (FeO NPs).

A highly sensitive DNAzyme-based SERS biosensor for quantitative detection of lead ions in human serum.

Lead ions (Pb), one form of the toxic heavy metal, have drawn significant attention due to their harmful effects on human health and the environment. Although many analytical techniques have been developed over the past few decades, the development of a sensitive, selective, and rapid method to detect Pb remains a challenge. In this work, we developed a sensitive surface-enhanced Raman scattering (SERS) biosensor for highly sensitive detection of Pb by using DNAzyme-modified FeO@Au@Ag nanoparticles (FeO@Au@Ag NPs).

A "turn-off" SERS aptasensor based DNAzyme-gold nanorod for ultrasensitive lead ion detection.

It is great significance to precisely monitor lead (II) ions (Pb) for environment protection and human health monitoring. We designed a sensitive detection strategy for sensitive and selective determination of Pb, based on a Pb-specific DNAzyme as the catalytic unit, Cy3-labeled DNA modified gold nanorods (AuNRs) as SERS reporter. Firstly, AuNRs surface were employed as a platform for the immobilization of thiolated probe DNA, and then hybridized with DNAzyme catalytic beacons.

A graphene oxide-based hairpin probe coupling duplex-specific nuclease signal amplification for detection and imaging of mRNA in living cells.

In situ imaging of mRNA in living cells can help to monitor the real time mRNA expression and also useful for diagnosis and prognosis of the diseases. In this study, a new strategy was designed for simple, sensitive, and selective platform to detect the mRNA levels by combining a hairpin probe-graphene oxide (HP1/GO) and duplex-specific nuclease signal amplification (DSNSA). Initially, the DNA probe was adsorbed on the surface of GO to protect it from enzymatic digestion.