Novel screening test for celiac disease using peptide functionalised gold nanoparticles

Figure 3 Testing peptide-coated AuNPs with anti-gliadin. A: Reduction in color from red to translucent and absorbance was observed in AuNP coated with peptide (S) and incubated with AGA at various dilutions (S1) 2 μg/mL, (S2) 4 μg/mL, (S3) 6 μg/mL, (S4) 8 μg/mL, (S5) 10 μg/mL), (S6) 12 μg/mL, (S7) 14 μg/mL, (S8) 16 μg/mL, (S9) 18 µg/mL and (S10) 20 μg/mL. No significant reduction in color or shift in peak wavelength was observed in peptide coated AuNP incubated with control rabbit IgG at dilutions (C1) 2 μg/mL, (C2) 4 μg/mL, (C3) 6 μg/mL, (C4) 8 μg/mL, (C5) 10 μg/mL), (C6) 12 μg/mL, (C7) 14 μg/mL, (C8) 16 μg/mL, (C9) 18 μg/mL and (C10) 20 μg/mL; B: Representation of specificity based on UV-Vis absorbance spectra for the antibody interactions at equal concentrations of AGA and control antibody; C: Colorimetric response curve plotted on AuNP coated with peptide following the addition of AGA at different dilutions. AGA: Anti-gliadin.