Herein, a reliable surface-enhanced Raman scattering (SERS)-active substrate has been prepared by synthesizing gold nanoparticles (AuNPs)-decorated MoS2 nanocomposite. The AuNPs grew in situ on the surface of MoS2 nanosheet to form efficient SERS hot spots by a spontaneous redox reaction with tetrachloroauric acid (HAuCl4) without any reducing agent. The morphologies of MoS2 and AuNPs-decorated MoS2 nanosheet were characterized by TEM, HRTEM, and AFM. The formation of hot spots greatly depended on the ratio of MoS2 and HAuCl4. When the concentration of HAuCl4 was 2.4 mM, the as-prepared AuNPs@MoS2-3 nanocomposite exhibited a high-quality SERS activity toward probe molecule due to the generated hot spots. The spot-to-spot SERS signals showed that the relative standard deviation (RSD) in the intensity of the main Raman vibration modes (1362, 1511, and 1652 cm–1) of Rhodamine 6G were about 20%, which displayed good uniformity and reproducibility. The AuNPs@MoS2-based substrate was reliable, sensitive, and reproducible, which showed great potential to be an excellent SERS substrate for biological and chemical detection.Keywords: AuNPs@MoS2 nanocomposite; hot spot; SERS-active substrate; uniformity

A 26 kilobase single strand DNA fragment was obtained from long-range PCR amplification and subsequent enzymatic digestion, which we folded into a super-sized DNA origami nanostructure by using ∼800 staple strands.

DNA nanostructures have recently emerged as a type of drug delivery nanocarriers due to their suitable sizes, well-defined structures and low-toxicity. Here, we present a protocol for the assembly of DNA nanoribbon structures with rolling circle amplification (RCA) and delivery of CpG oligonucleotide. DNA nanoribbons with different dimensions and patterns were assembled with long RCA strands and several short staples. Significantly, we demonstrated they exhibited high-efficiency cellular uptake and improved immunostimulatory activity compared with ss- or ds- DNA.

A 26 kilobase single strand DNA fragment was obtained from long-range PCR amplification and subsequent enzymatic digestion, which we folded into a super-sized DNA origami nanostructure by using ∼800 staple strands.