Combination of optical activity with surface-enhanced Raman scattering has been a dream of physical chemists for a long time. We report a measurement protocol based on silver colloids and aromatic linkers where chiral acids could be detected in concentrations of about 10-5 M. We explain the mechanism by binding and self-assembly of the linkers into chiral aggregates on the silver surface. Following the "sergeants-and-soldiers" principle, the chirality is determined by the relatively minor acidic component. Such detection of biologically relevant molecules may be useful when other methods, such as electronic circular dichroism, are not sensitive enough. In the future, variations of the chemical structure of the linker or other conditions are needed to provide a more specific signal allowing one to better discriminate among the optically active molecules.

Department of Analytical Chemistry University of Chemistry and Technology Technická 5 Prague 16628 Czech Republic

Department of Optics Palacký University Olomouc 17 listopadu 12 Olomouc 77146 Czech Republic

Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 Prague 16610 Czech Republic

Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 Prague 16610 Czech Republic and Department of Analytical Chemistry University of Chemistry and Technology Technická 5 Prague 16628 Czech Republic

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