NotesFAQContact Us
Collection
Advanced
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ913391
Record Type: Journal
Publication Date: 2010-Apr
Pages: 4
Abstractor: As Provided
Reference Count: 14
ISBN: N/A
ISSN: ISSN-0021-9584
Surface-Enhanced Resonance Raman Scattering and Visible Extinction Spectroscopy of Copper Chlorophyllin: An Upper Level Chemistry Experiment
Schnitzer, Cheryl S.; Reim, Candace Lawson; Sirois, John J.; House, Paul G.
Journal of Chemical Education, v87 n4 p429-432 Apr 2010
Advanced chemistry students are introduced to surface-enhanced resonance Raman scattering (SERRS) by studying how sodium copper chlorophyllin (CuChl) adsorbs onto silver colloids (CuChl/Ag) as a function of pH. Using both SERRS and visible extinction spectroscopy, the extent of CuChl adsorption and colloidal aggregation are monitored. Initially at pH[is asymptotically equivalent to]10, the colloids possess an overall negative surface charge, preventing attraction. Surface-enhanced Raman scattering (SERS) is not detected at that pH because the relatively small colloids do not possess a surface plasmon in resonance with the laser excitation frequency (633 nm). Once the solution pH decreases slightly, colloidal clusters form and SERRS is detected. As the pH is lowered to a value of 4 or 3, protonation of CuChl results in colloidal aggregation and precipitation. If adsorption and aggregation are halted by adding H[subscript 2]SO[subscript 4](aq) and then NaOH(aq), an intense SERRS signal is steadily detected from acidic pH (about 4), back to the initial basic pH (about 10). (Contains 3 figures.)
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Evaluative
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A