Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• and Discussion Ligand synthesis. The ligands used in this work are depicted in Figure 1. All of them derived from lipoic acid, which was chosen as the anchor group because the immobilization of a cyclic disulfide on gold involves the formation of two Au–S bonds, causing the ligands to have a smaller

• obtained in a similar fashion by using (R)-lipoic acid in the coupling reaction. The ligand 2 contained a peripheral 2,2'-dipicolylamine residue for zinc(II) coordination. This group was separated from the lipoic acid anchor group by a C12 chain to ensure that it had a sufficient distance from the

• nanoparticle surface after immobilization. Compound 2 was prepared by starting from potassium phthalimide and 1,12-dibromododecane (Scheme 2). The product resulting from this step was treated with bis(2-pyridylmethyl)amine to give a DPA derivative that was coupled to (R)-lipoic acid after deprotection to

Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues

• Leon Buschbeck,
• Aleksandra Markovic,
• Gunther Wittstock and
• Jens Christoffers

Beilstein J. Org. Chem. 2019, 15, 981–991, doi:10.3762/bjoc.15.96

• sequence including one deprotection reaction. One functional unit is α-lipoic acid (ALA) for binding the dye to gold surfaces. It was introduced to the DAT scaffold by an amidation reaction. The other functional unit is a para-(trifluoromethyl)benzyl group for facile detection of the surface-bound material

• indicated that trifluoromethylation is an excellent tool for the detection of surface-bound materials by XPS. Keywords: chromophore; diaminoterephthalate; fluorine surface marker; fluorescence dye; lipoic acid; self-assembled monolayers; Introduction Diaminoterephthalates (DATs) are powerful fluorescence

• α-lipoic acid (ALA) residue. Furthermore, a fluorine-substituted moiety bound to DAT shall facilitate detection by XPS. Results and Discussion Synthesis. The preparation of DAT–ALA conjugate 3 with a fluorinated residue started from mono-carbamate-protected diethyl DAT 1 (Scheme 1). Compound 1 was

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• desired protein. After washing and cleavage steps, the protein can be fully analyzed. Reprinted from [81]. Published by The Royal Society of Chemistry. Design of the fiber-type “Sugar Chips”. AuNPs are firstly immobilized on an optical fiber functionalized with α-lipoic acid (TA fiber). Successively