Work

Bisignate Surface-Enhanced Raman Optical Activity with Analyte-Capped Colloids

Year: 2025

Type: article

Abstract: Spectroscopic detection of chiral compounds is often hampered by a low sensitivity. For Raman optical activity (ROA), the signal can be dramatically increased in surface-enhanced experiments. So far, however, reproducible surface-enhanced ROA (SEROA) spectra were obtained for a reporter molecule only via induced chirality, and the intensities were just proportional to the Raman scattering. In the present study, we show that the signal can be substantially increased if colloidal silver nanoparticles are prepared already in the presence of a chiral analyte. In this case, both the analyte's and reporter's bands are visible. In addition, some experiments provided bisignate SEROA patterns, thus significantly enhancing information about the molecular structure provided by this spectroscopic method. Increased electronic circular dichroism (ECD) of the capped aggregated colloids suggests that ECD and polarized Raman scattering (ECD-Raman) contribute to the monosignate SEROA intensities, while well-dispersed nonaggregating colloids are important for observation of true (bisignate) molecular vibrational SEROA.

Source: ACS Nano

DOI: 10.1021/acsnano.4c19027

Authors: Moumita Das, Debraj Gangopadhyay, Valery Andrushchenko, Josef Kapitán, Petr Bouř

Institutions: Czech Academy of Sciences, Czech Academy of Sciences, Institute of Organic Chemistry and Biochemistry, University of Chemistry and Technology, Prague, Palacký University Olomouc

Language: English

Topic: Gold and Silver Nanoparticles Synthesis and Applications

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funder: Grantová Agentura České Republiky