Colorimetric Detection System for Salmonella typhimurium Based on Peroxidase-Like Activity of Magnetic Nanoparticles with DNA Aptamers

Figure 6

Optimization of parameters for the colorimetric system. Acetate buffer at pH 4.0 was optimal for TMB oxidation (a). MNP concentration of 400 μg/mL (b), TMB concentration of 40 μM (c), H₂O₂ concentration of 35 mM (d), and incubation time of 10 min (e) yielded optimal effectiveness.

(a)

(b)

(c)

(d)

(e)