title: Electrochemical investigation of the interaction between lysozyme-shelled microbubbles and vitamin C.
abstract: We report loading of vitamin C (ascorbic acid) on to lysozyme-shelled microbubbles. The interaction between lysozyme-shelled microbubbles and vitamin C was studied by use of cyclic and differential pulse voltammetry, zeta potential measurements, and scanning electron microscopy. The effect of microbubbles on electrochemical measurement of ascorbic acid was evaluated. The linear range for ascorbic acid obtained for differential pulse measurement in the presence of 1 mg mL(-1) microbubbles was 1-50 μmol L(-1) (y = 0.067x + 0.130, r(2) = 0.995), with a detection limit of 0.5 μmol L(-1). The experimental conditions, i.e., pH and ionic strength, were optimized to improve the interaction between ascorbic acid and lysozyme-shelled microbubbles. The results were satisfactory when the interaction was performed for 1 h in aqueous solution at pH 6. The amount of vitamin C loaded on the microbubbles (90% of the analyte added, RSD(inter-expt.) = 3%, n = 6) and the stability of microbubbles-ascorbic acid complex (until 72 h at 25 °C) were also evaluated by use of differential pulse voltammetry and zeta potential measurements.
authors.affiliation: Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 00173 Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cavalieri
authors.forename: Laura
authors.initials: L
authors.lastname: Micheli
authors.forename: Meifang
authors.initials: M
authors.lastname: Zhou
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Tortora
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Palleschi
authors.forename: Muthupandian
authors.initials: M
authors.lastname: Ashokkumar
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D004337:Drug Carriers; D004355:Drug Stability; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D045423:Microbubbles; D008855:Microscopy, Electron, Scanning; D009113:Muramidase / Q000737:chemistry*; D009994:Osmolar Concentration; D012996:Solutions
chemical_list: D004337:Drug Carriers; D012996:Solutions; D009113:Muramidase; D001205:Ascorbic Acid