Preparation of gold nanoparticles loaded MOF-199 for SERS detection of 5-hydroxyindole-3-acetic acid in serum.

5-Hydroxyindole-3-acetic acid (5-HIAA) is regarded as a biomarker for diagnosis of carcinoid tumors, and it is of great significance to developing a precision assay for monitoring 5-HIAA levels. In this work, gold nanoparticles loading on the surface of MOF-199 (Au NPs/MOF-199) is prepared to propose a surface enhanced Raman scattering (SERS) assay for 5-HIAA. When 4-mercaptopyridine (4-MPy) is used as a SERS probe, on Au NPs/MOF-199, limit of detection (LOD) at 10 mol/L can be achieved.

MnO coated Au nanoparticles advance SERS detection of cellular glutathione.

Glutathione, referred to as GSH, abnormal physiologic level of GSH is an indication to some neurodegenerative diseases and cancers. A measurement of cellular GSH calls for rapid, sensitive, and selective methods. In this work, we rationally design and prepare Au@MnO core-shell composite nanoparticles combining with tetramethylbenzidine (TMB) molecules to determine intracellular GSH by Surface enhanced Raman scattering (SERS) technique.

A rapid and quantitative method for assessing the whiteness of whitened lignin based on an in-depth analysis of reported methods.

The modification of lignin to a lighter color has been a concern in lignin valorization. In the previous reports on lignin color reduction, the methods of assessing the whiteness of lignin varied from each other, due to the absence of a universal method for characterizing the lightness/darkness of dark samples. In this paper, the reported methods for assessing the whiteness of lignin were analyzed, including "comparison of absorbance curve", "absorbance at specific wavelength", "ISO or TAPPI brightness" and "photograph observation".