Amyloid-beta-binding peptides and the use thereof for the treatment and diagnosis of alzheimer's disease

1. A peptide comprising an amino acid sequence which binds to amyloid beta species and in which the negative charge of its free C-terminus carboxyl group was removed by modification such that no charge or a positive charge is present at said free C-terminus,

wherein the amino acid sequence is SEQ ID NO: 12, and

wherein the free C-terminus carboxyl group is replaced with an acid amide group (CONH2 group), a COH group, a CONH-alkyl group or a CONH-alkyl amine group, and

wherein the peptide's binding affinity to the amyloid beta species is increased as compared to an analogous peptide without the C-terminus modification.