Biosynthesis and computational analysis of amine-ended dual thiol ligand functionalized gold nanoparticles for conventional spectroscopy detection of melamine

- Preparation of Dual thiol ligands functionalized gold nanoparticles (DTAuNPs)
- Characterization of DTAuNPs by using UV, TEM, FTIR, DLS and SEM with EDX
- Melamine was determined using DTAuNPs by spectrophotometry
- DTAuNPs induced cytotoxicity and decreased proliferation in A549 cells
- Good relationship of theoretical and experimental data

The bio-synthesized DTAuNPs have an average size of 21 nm. The aggregation extent depends on the concentration of melamine, which was validated by UV-vis spectra and visual method of melamine detection was developed. The major observation in this method was the color change of DTAuNPs from red to purple due to the aggregation of ligand capped gold nanoparticles instigated by melamine. The reaction of color changes were processed due to the shifting of bonding in hydrogen in between nanoparticles and melamine. The aggregation extent depends on the concentration of melamine, which can be validated UV-vis spectra and visual method of detecting melamine is developed. The electron density and conventional UV-vis, FTIR spectroscopy and DFT studies on the ligand was performed using computational methods. The theoretical and experimental data for the energy transitions and the molar extinction coefficients of the ligands studied has been obtained. Further, the ligand capped gold nanoparticles was assessed for cytotoxicity against A549 cells which resulted in significant decrease in cell viability was noted in 50 μg/mL DTAu, 4-ATP and AXT treated cells at 2 h (85% and 66%) and 6 h (83% and 36%) respectively, (p < 0.01) were studied and reported in this manuscript.

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