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The interaction between dengue virus particles (DENV), sedimentation hemagglutinin particles (SHA), dengue virus envelope protein (Eprot), and solid surfaces was investigated by means of ellipsometry and atomic force microscopy (AFM). The surfaces chosen are bare Si/SiO2 wafers and Si/SiO2 wafers covered with concanavalin A (ConA), jacalin (Jac), polystyrene (PS), or poly(styrene sulfonate) (PSS) films. Adsorption experiments at pH 7.2 and pH 3 onto all surfaces revealed that (i) adsorption of DENV particles took place only onto ConA under pH 7.2, because of specific recognition between glycans on DENV surface and ConA binding site; (ii) DENV particles did not attach to any of the surfaces at pH 3, suggesting the presence of positive charges on DENV surface at this pH, which repel the positively charged lectin surfaces; (iii) SHA particles are positively charged at pH 7.2 and pH 3 because they adhered to negatively charged surfaces at pH 7.2 and repelled positively charged layers at pH 3; and (iv) SHA particles carry polar groups on the surface because they attached to silanol surfaces at pH 3 and avoided hydrophobic PS films at pH 3 and pH 7.2. The adsorption behavior of Eprot at pH 7.2 revealed affinity for ConA>Jac>PSS>PS≈bare Si/SiO2 layers. These findings indicate that selectivity of the Eprot adsorption is higher when it is part of virus structure than when it is free in solution. The correlation between surface energy values determined by means of contact angle measurements and DENV, SHA, or Eprot adsorption behavior was used to understand the intermolecular forces at the interfaces. A direct correlation was not found because the contributions from surface energy were probably surpassed by specific contributions.

a b s t r a c tCharacterization of Sterculia striata polysaccharide (SSP) films adsorbed onto Si wafers from solutions prepared in ethyl methyl imidazolium acetate (EmimAc), water or NaOH 0.01 mol/L was systematically studied by means of ellipsometry, atomic force microscopy and contact angle measurements. SSP adsorbed from EmimAc onto Si wafer as homogeneous monolayers (∼0.5 nm thick), while from water or NaOH 0.01 mol/L SSP formed layers of ∼4.0 nm and ∼1.5 nm thick, respectively. Surface energy values found for SSP adsorbed from EmimAc or water were 68 ± 2 mJ/m 2 and 65 ± 2 mJ/m 2 , respectively, whereas from NaOH it amounted to 57 ± 3 mJ/m 2 . The immobilization of lysozyme (LYS) onto SSP films was also investigated. The mean thickness of LYS (d LYS ) immobilized onto SSP films adsorbed from each solvent tended to increase with the decrease of p S and total S . However, the enzymatic activity of LYS molecules was higher when they were immobilized onto SSP films with higher p S and total S values.