SURFACE-ENHANCED RAMAN-SPECTROSCOPIC MONITOR OF P-ACNES LIPID HYDROLYSIS IN-VITRO

Surface enhanced Raman spectroscopy (SERS) at a silver microelectrode was used to monitor bacterial hydrolysis of triglycerides in lipid mix tures that model sebaceous gland secretions. Mixtures of wax esters, s qualene, triolein, and triisostearin were used as model skin secretion s. The transformation was followed in vitro as changes in the SERS cau sed by hydrolysis of triglyceride to fatty acid. The fatty acid was ad sorbed as its carboxylate, which is readily identified by the characte ristic band at ca. 1395 cm(-1). Coadsorption of propionate was also ob served. The technique can also confirm the presence of bacteria by det ection of short chain carboxylic acids released as products of ferment ation during the growth of these cells.