Plasmonic nanohalo optical probes for highly sensitive imaging of survivin mRNA in living cells.

A strategy is designed for sensitive detection of tumor biomarker survivin mRNA based on resonance Rayleigh scattering of a single AuNP nanohalo probe that couples large gold nanoparticles (L-AuNPs, 52 nm) with small AuNPs (S-AuNPs, 18 nm) through the affinity interaction between streptavidin and biotin. This core-satellite plasmon ruler is further applied to imaging survivin mRNA in living cells.

Oriented assembly of invisible probes: towards single mRNA imaging in living cells.

Due to the complexity of biological systems and the ultralow concentration of analytes, improving the signal-to-noise ratio and lowering the limit of detection to allow highly sensitive detection is key to biomolecule analysis, especially intracellular analysis. Here, we present a method for highly sensitive imaging of mRNA in living cells by using novel invisible oriented probes to construct a turn-on signal generation mechanism from zero background. Two DNA probes (S1 and S2) are asymmetrically modified on two small gold nanoparticles (AuNPs) with a diameter of 20 nm.

Dual-Wavelength Electrochemiluminescence Ratiometry Based on Resonance Energy Transfer between Au Nanoparticles Functionalized g-C3N4 Nanosheet and Ru(bpy)3(2+) for microRNA Detection.

Here, a dual-wavelength ratiometric electrochemiluminescence (ECL) approach is reported based on resonance energy transfer (RET) from graphite-like carbon nitride nanosheet (g-C3N4 NS) to Ru(bpy)3(2+) for sensitive detection of microRNA (miRNA). In this approach, Au nanoparticles (Au NPs) functionalized g-C3N4 NS nanohybrid (Au-g-C3N4 NH) coated on glassy carbon electrode (GCE) could exhibit strong and stable ECL emissions with emission peak centered at 460 nm. The ECL emission at such wavelength matched well with the absorption peak of Ru(bpy)3(2+) as well as impeccably stimulating the emission of Ru(bpy)3(2+) at the wavelength of 620 nm, producing ECL-RET with high efficiency.