Digital DNA detection based on a compact optofluidic laser with ultra-low sample consumption

DNA lasers self-amplify optical signals from a DNA analyte as well as thermodynamic differences between sequences, allowing quasi-digital DNA detection. However, these systems have drawbacks, such as relatively large sample consumption and complicated dye labelling. Moreover, although the lasing signal can detect the target DNA, it is superimposed on an unintended fluorescence background, which persists for non-target DNA samples as well. From an optical point of view, it is thus not truly digital detection and requires spectral analysis to identify the target. In this work, we propose and demonstrate an optofluidic laser that has a single layer of DNA molecules as the gain material. A target DNA produces intensive laser emission comparable to existing DNA lasers, while any unnecessary fluorescence background is successfully suppressed. As a result, the target DNA can be detected with a single laser pulse, in a truly digital manner. Since the DNA molecules cover only a single layer on the surface of the laser microcavity, the DNA sample consumption is a few orders of magnitude lower than that of existing DNA lasers. Furthermore, the DNA molecules are stained by simply immersing the microcavity in the intercalating dye solution, and thus the proposed DNA laser is free of any complex dye-labelling process prior to analysis.

A simple and sensitive resonance light scattering method based on aggregation of gold nanoparticles for selective detection of microRNA-21

A novel resonance light scattering method based on analyte-induced aggregation of gold nanoparticles for the determination of microRNAs was developed.

A simple cyanide sensing probe based on Ag/Fe3O4nanoparticles

The first direct approach in ultra-trace cyanide determination through a simple, selective and rapid reaction by simply-synthesized recyclable Ag/Fe₃O₄nanostructures.

Combining a loop-stem aptamer sequence with methylene blue: a simple assay for thrombin detection by resonance light scattering technique

Schematic illustration of the RLS aptasensor for selective detection of human thrombin.

Study on the interaction between emodin and ethyl violet by resonance Rayleigh scattering technique

EV-EMO system. C_EMO(1–8) 0, 0.4, 1.0, 1.5, 2.3, 3.2, 3.8, 4.2 μg mL⁻¹; C_EV: 1.2 × 10⁻⁵ mol L⁻¹; pH 7.0.