Figure 5.

Examination of interference species effects. (A) UV–Vis absorption spectra of the samples (0.2 mL) containing E. coli O157:H7 (OD₆₀₀ = ~1) with the inferences species including sodium chloride (1 mM), potassium chloride (1 mM), creatinine (1 mM), bovine serum albumin (1 mM), and histamine (1 mM) obtained after reaction with H₂O₂ (11.2 mM) and TMB (1.25 mM) for 25 min followed by the addition of sulfuric acid (2 M, 2 μL) to stop the reaction. All the samples were prepared in the phosphate buffer at pH 3. (B) Photograph of the samples (0.2 mL) containing S. aureus (OD₆₀₀ = 1) with interferences including sodium chloride (1 mM), potassium chloride (1 mM), creatinine (1 mM), bovine serum albumin (1 mM), and histidine (1 mM), obtained after the reaction with H₂O₂ (180 mM) for 5 min.