Figure 3. θ vs. [phage] curves for two phage systems, (A) T4 and (B) P22. θ is the fraction of total area of adsorbed analyte over the total surface area, called surface coverage. Langmuir: T4, R² = 0.42; P22, R² = 0.15. Freundlich: T4, R² = 0.81; P22, R² = 0.87. Brouers-Sotolongo: T4, R² = 0.99, θ_max = 0.29, K = 4.96 × 10⁻¹⁵, α = 2.68; P22, R² = 0.99, θ_max = 0.13, K = 5.26 × 10⁻⁹, α = 0.80. (C) Diffusion-controlled transport of bacteriophages to Au-DTSP planar surface, using low bulk concentration of phage to prevent phage clustering and steric hindrance to attachment. Pure/unpure ratios: T4W = 2.1x; P22 = 1.6x; CP1 = 3.0x. (D) Surface plasmon resonance plot of purified T4 immobilization to planar Au surface treated with reactive DTSP self-assembled monolayer.