The thermodynamics of adsorption of gallic acid (GA, 3,4,5-trihydroxylbenzoic acid) on the hanging mercury drop electrode (HMDE) surface was studied by temperature-dependent stripping voltammetry (TD-SV), at physiological pH 7.4. The thermodynamic parameters, e.g., Gibbs free energy, Delta G(ADS), enthalpy, Delta H(ADS) and entropy, Delta S(ADS), of adsorption have been determined at physiological temperatures 2-40 degrees C. Chemisorption of the radical species =[GA(OH)(2)(O(-))](center dot) is the energetically important reaction. The thermodynamic data show a complex mechanism of adsorption of GA on the electrode surface, which is strongly dependent on temperature. At low-temperatures T<12 degrees C, adsorption is controlled by enthalpy, while at T>22 degrees C, adsorption is entropy driven. In the temperature range 12 degrees C and 22 degrees C, a combined enthalpy-entropy stabilization occurs. A mechanism is proposed which analyses the implication of thermodynamics to the interfacial adsorption of polyphenols with cell membranes under physiological conditions. Copyright (C) 2011 Elsevier Inc. All rights reserved.