השוואת שיטות

	ATR-FTIR	דיכרואיזם מעגלי	SERS
תחום	ספקטרוסקופיה	ספקטרוסקופיה	ספקטרוסקופיה
משפחה	Process / pipeline	Process / pipeline	Process / pipeline
שנת המקור	1961	1969	1974
הוגה השיטה	Joop Fahrenfort	Jean-Claude Fasman	Martin Fleischmann
סוג	Vibrational spectroscopy technique	Spectroscopic method	Vibrational spectroscopy technique
מקור מכונן	Harrick, N. J. (1960). Study of physics of internal reflection from metals. Journal of Physics and Chemistry of Solids, 13(2), 143-155.	Greenfield, N. J., & Fasman, G. D. (1969). Computed circular dichroism spectra for protein secondary structures. Biochemistry, 8(10), 4108-4116.	Fleischmann, M., Hendra, P. J., & McQuillan, A. J. (1974). Raman spectra of pyridine adsorbed at a silver electrode. Chemical Physics Letters, 26(2), 163-166.
כינויים	ATR-IR, attenuated total reflectance, FTIR spectroscopy	CD spectroscopy, circular dichroism, CD analysis	Surface-enhanced Raman scattering, SERS spectroscopy
קשורות	3	3	3
תקציר	Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FTIR) spectroscopy is a variant of conventional FTIR that measures infrared absorption through evanescent-wave interrogation of samples in direct contact with a high-refractive-index crystal. Developed by Harrick and Fahrenfort in the 1960s, ATR-FTIR is now the dominant form of FTIR spectroscopy, enabling rapid, non-destructive characterization of organic compounds, polymers, coatings, and biological materials without extensive sample preparation.	Circular Dichroism (CD) spectroscopy measures the differential absorption of left- and right-circularly polarized light by optically active molecules, particularly proteins and nucleic acids. Introduced by Greenfield and Fasman in 1969, CD is a rapid, non-destructive technique for characterizing secondary structure (alpha-helix, beta-sheet), monitoring protein folding transitions, and assessing conformational changes in response to pH, temperature, or ligand binding.	Surface-Enhanced Raman Spectroscopy (SERS) amplifies weak Raman signals by many orders of magnitude when analyte molecules are adsorbed on specially prepared metal (typically silver or gold) nanostructured surfaces. Discovered by Fleischmann, Hendra, and McQuillan in 1974, SERS enables detection of vibrational signatures of single molecules and ultra-trace contaminants, revolutionizing analytical chemistry and forensics.