Resonance Raman spectra for the in-situ identification of bacteria strains and their inactivation mechanism

AbstractThe resonance Raman spectra of bacterial carotenoids have been employed to identify bacterial strains and their intensity changes as a function of ultraviolet(UV) radiation dose have been used to differentiate between live and dead bacteria. The enhanced resonance Raman spectra of color-pigmented bacteria were recorded after excitation with visible light diode lasers. In addition, the resonance enhanced Raman spectra enabled us to detect bacteria in water at much lower concentrations (~108 cells/mL) than normally detected spectroscopically. A handheld spectrometer capable of recording resonance Raman spectra in-situ was designed, constructed and was used to record the spectra. In addition to bacteria, the method presented in this paper may also be used to identify fungi, viruses and plants, in-situ, and detect infections within a very short period of time.

Download Full-text

Resonance Raman Spectra for the In Situ Identification of Bacteria Strains and Their Inactivation Mechanism

Applied Spectroscopy ◽

10.1177/0003702821992834 ◽

2021 ◽

pp. 000370282199283

Author(s):

Dinesh Dhankhar ◽

Anushka Nagpal ◽

Runze Li ◽

Jie Chen ◽

Thomas C. Cesario ◽

...

Keyword(s):

Radiation Dose ◽

Raman Spectra ◽

Resonance Raman ◽

Bacterial Strains ◽

Short Period ◽

Intensity Changes ◽

Inactivation Mechanism ◽

Identification Of Bacteria ◽

Resonance Raman Spectra

The resonance Raman spectra of bacterial carotenoids have been employed to identify bacterial strains and their intensity changes as a function of ultraviolet (UV) radiation dose have been used to differentiate between live and dead bacteria. In addition, the resonance-enhanced Raman spectra enabled us to detect bacteria in water at much lower concentrations (∼108 cells/mL) than normally detected spectroscopically. A handheld spectrometer capable of recording resonance Raman spectra in situ was designed, constructed, and was used to record the spectra. In addition to bacteria, the method presented in this paper may also be used to identify fungi, viruses, and plants, in situ, and detect infections within a very short period of time.

Download Full-text

The resonance Raman spectra and excitation profiles of some 4-sulfamylazobenzenes

Canadian Journal of Chemistry ◽

10.1139/v77-203 ◽

1977 ◽

Vol 55 (9) ◽

pp. 1444-1453 ◽

Cited By ~ 28

Author(s):

Kamal Kumar ◽

P. R. Carey

Keyword(s):

Raman Spectrum ◽

Raman Spectra ◽

Resonance Raman ◽

Valence Bond ◽

Wavelength Dependence ◽

Accurate Estimation ◽

Intensity Changes ◽

Stretching Vibration ◽

Resonance Raman Spectra ◽

Frequency Changes

The resonance Raman spectra of three pharmacologically important sulfonamides, 4-sulfamyl-4′-dimethylaminoazobenzene (1), 4-sulfamyl-4′-hydroxyazobenzene (2), and 4-sulfamyl-4′-aminoazobenzene (3), are compared with those of analogues lacking the sulfonamide group. The —SO2NH2 moiety does not directly contribute intense or moderately intense bands to the resonance Raman spectra of 1, 2, and 3. However, —SO2NH2 ionization is reflected by frequency changes in a band near 1140 cm−1 and intensity changes in the 1420 cm−1 region. The normal Raman spectrum of 2 confirms that the intensity changes reflect —SO2NH2 ionization rather than unrelated changes in vibronic coupling. The effect of —OH ionization on the resonance Raman spectrum of 2 emphasizes that caution must be exercised when relating spectral perturbations to changes in contributions from valence bond type structures. Resonance Raman excitation profiles for the 1138, 1387, and 1416 cm−1 bands of 2 show that these bands gain intensity by coupling with the electronic transitions in the 240 to 450 nm region and that, more than 1000 cm−1 to the red of λmax, the wavelength dependence can be closely reproduced by the FB type terms of Albrecht and Hutley. The excitation profile for each band shows evidence for structure in the 470 nm region, although lack of sufficient excitation wavelengths prevents accurate estimation of the spacing. Under conditions of rigorous resonance the intense Raman lines all occur in the 1400 cm−1 region, i.e. they are 'bunched' in the region known to contain the —N=N— stretching vibration.

Download Full-text

A Resonance Raman Method for the Rapid Detection and Identification of Bacteria in Water

Applied Spectroscopy ◽

10.1366/0003702804730790 ◽

1980 ◽

Vol 34 (1) ◽

pp. 72-75 ◽

Cited By ~ 31

Author(s):

W. F. Howard ◽

W. H. Nelson ◽

J. F. Sperry

Keyword(s):

Raman Spectra ◽

Rapid Detection ◽

Resonance Raman ◽

Aqueous Dispersion ◽

Incident Radiation ◽

Detection And Identification ◽

Identification Of Bacteria ◽

Resonance Raman Spectra ◽

Combination Bands

Resonance Raman spectra are reported for 16 types of carotene-containing bacteria and algae in aqueous dispersion. Spectra are obtained with ease from organisms grown in culture and collected by centrifugation. In many instances spectra produced with 488 nm incident radiation are sufficiently unique to provide a basis for identification. While most information is contained in the 900 to 1600 cm−1 region, several bacteria exhibit pronounced carotenoid overtone and combination bands which can be assigned along with the fundamental vibrations.

Download Full-text