Computer Assisted Examination of Infrared and Near Infrared Spectra to Assess Structural and Molecular Changes in Biological Samples Exposed to Pollutants: A Case of Study

Abstract

Abstract:We present a computer assisted method for the examination of the structural changes present in the probe organism Vicia faba exposed to inorganic arsenic, detected by means of Fourier transform infrared (FTIR) and Fourier transform near infrared (FTNIR) spectroscopy. Like the common ecotoxicological tests, the method is based on the comparison among control and exposed sample spectra of the organisms to detect structural changes caused by pollutants. Using FTIR spectroscopy, we measured and plotted the spectral changes related to the unsaturated to saturated lipid ratio changes (USL), the lipid to protein ratio changes (LPR), fatty and ester fatty acid content changes (FA), protein oxidation (PO) and denaturation, and DNA and RNA changes (DNA-RNA). Using FTNIR spectroscopy, we measured two spectral ranges that belonged to hydrogen bond interactions and aliphatic lipid chains called IntHCONH and Met1overt, respectively. The FTIR results showed that As modified the DNA-RNA ratio and also caused partial protein denaturation in the Vicia faba samples. The FTNIR results supported the FTIR results. The main advantage of the proposed computational method is that it does not require a skilled infrared or near infrared operator, lending support to conventional studies performed by toxicological testing.

Targeted photodynamic therapy treatment of in vitro A375 metastatic melanoma cells

“…FT-IR spectroscopy has various applications in structural identification, and can be used for qualitative analysis of molecular ligand and absorption bond formations, as well as peptide bond identification within the final PS drug conjugate (Figure 5) [26–29]. FT-IR characterization results revealed the presence of Au-S ligand exchange bonding, since the spectra of control conjugate ZnPcS 4 - AuNP-PEG5000-SH-NH 2 , noted a C-S (1050-1200 cm –1 ) stretch shift, suggesting AuNP-PEG5000-SH-NH 2 lost their C-S groups to bond with ZnPcS 4 [26, 27].…”

“…Moreover, the presence of Au-S ligand exchange bonding was confirmed since the FT-IR spectra of ZnPcS 4 - AuNP-PEG5000-SH-NH 2 noted a loss of a C-S (1200 cm –1 ) sharp band when compared to ZnPcS 4 alone, suggesting ZnPcS 4 lost its C-S groups to bond with AuNP-PEG5000-SH-NH 2 [28]. Finally, the FT-IR spectra of ZnPcS 4 - AuNP-PEG5000-SH-NH 2 noted a sharp S-S (500-540 cm –1 ) bend suggesting that ligand absorption between the sulphonated ZnPcS 4 PS and AuNP-PEG5000-SH-NH 2 occurred to form a weak di-sulphide bond [29].…”

“…Furthermore, the final molecular conjugate (ZnPcS 4 - AuNP-PEG5000-SH-NH 2 - Anti-MIA Ab) was also subjected to FT-IR analysis for confirmatory amide bond analysis, by noting and identifying the formation of amide bonds when compared to the FT-IR spectra of AuNP-PEG5000-SH-NH 2 alone (Figure 6). With referral to Figure 6, FT-IR characterization revealed that final molecular conjugate noted a C=O (1680-1630 cm –1 ) stretch and sharp N=H bend (1640-1650 cm –1 ), when compared to the AuNP-PEG5000-SH-NH 2 alone, suggesting that strong primary and secondary amide peptide bonds (CO-NH) formed between the amine (NH 2 ) functionalized group on the AuNPs and the activated c’ terminus of the Anti-MIA Ab [29].…”

Development and characterization of a novel l-asparaginase/MWCNT nanobioconjugate

“…9, Zone C), corresponding to the vibrations of C-C, C-O, C-N, N-H and C-H bonds in amino acids structure. 57 Raman spectroscopy allows to examine the changes in the MWCNTs surface aer ASNase immobilization. The spectra of both pristine MWCNTs and ASNase-MWCNTs bioconjugate (Fig.…”

The Synthesis and Characterisations of Porous Thioamide-Sulfonated-Modified Poly (Acrylonitrile-<em>Co</em>-Divinylbenzene-80) as a Potential Sorbent to Capture Polar Analytes

“…The absorption band at the region ~1600.57 cm -1 was due to the carboncarbon stretching vibrations in the aromatic ring. Strong absorption band at 1700 cm -1 was due to the presence of the carbonyl (C=O) stretching vibrations [42]. The absorptions at ~900 cm -1 , ~830 cm -1 and ~790 cm -1 were due to the C-H bonds in the benzene rings of meta (m) and para (p) in DVB units.…”