Characterization of human Urotensin II peptide adsorbed on silver electrode by surface-enhanced Raman scattering spectroscopy.

The cyclic human neuropeptide Urotensin II (hU-II) is an important regulatory peptide found in the central nervous system, cardiovascular system, kidney, etc., however, its conformational structure and dynamics in aqueous solutions have not been studied in detail experimentally. In the present study, the structure of hU-II and the mechanism of its adsorption on the electrochemically roughened Ag electrode are investigated using electrochemical surface-enhanced Raman scattering spectroscopy (EC-SERS) in the voltage range from -1.

Stable and Reusable Lace-like Black Silicon Nanostructures Coated with Nanometer-Thick Gold Films for SERS-Based Sensing.

We propose a simple, fast, and low-cost method for producing Au-coated black Si-based SERS-active substrates with a proven enhancement factor of 10. Room temperature reactive ion etching of silicon wafer followed by nanometer-thin gold sputtering allows the formation of a highly developed lace-type Si surface covered with homogeneously distributed gold islands. The mosaic structure of deposited gold allows the use of Au-uncovered Si domains for Raman peak intensity normalization.

Visualizing hypochlorous acid production by human neutrophils with fluorescent graphene quantum dots.

In living organisms, redox reactions play a crucial role in the progression of disorders accompanied by the overproduction of reactive oxygen and reactive chlorine species, such as hydrogen peroxide and hypochlorous acid, respectively. We demonstrate that green fluorescence graphene quantum dots (GQDs) can be employed for revealing the presence of the hypochlorous acid in aqueous solutions and cellular systems. Hypochlorous acid modifies the oxygen-containing groups of the GQD, predominantly opens epoxide ring C-O-C, forms excessive C=O bonds and damages the carbonic core of GQDs.