A rapid and reversible colorimetric assay for the characterization of aminated solid surfaces.
The covalent immobilization of synthetic or natural macromolecular compounds containing amino groups onto polystyrene (PS) solid surfaces is of great interest in diagnostic applications. A sensitive assay allowing the determination of reactive end groups is therefore a powerful tool for predicting the performance of the active surface. Recently, we reported the use of the Coomassie brilliant blue (CBB) colorimetric reagent to quantify protonated groups (N(+)) in linear and dendritic structures in solution (Coussot et al., Polym Int 58(5):511-518, 2009). In this work, a simple method using CBB dye for the characterization of PS aminated solid surfaces is developed. The proposed amino density estimation by colorimetric assay (ADECA) method is based on the reversible complexation of the dye with the N(+) groups on solid surfaces. The assay measures the released dye thanks to the use of a unique sodium carbonate-methanol buffer. Thereby, for the first time, the same surface can be used for characterization and for further coupling applications. A surface density of four N(+) groups per square nanometer can be measured in PS microwell format, the whole characterization being done within 30 min. Performances of this new colorimetric-based method are detailed. The ADECA method is further demonstrated to be useful for the characterization of aminated polypropylene and glass materials with various sizes and shapes.
Institut des Biomolécules Max Mousseron, UMR 5247, CNRS-Université de Montpellier 1-Université de Montpellier 2, Place Eugène Bataillon CC 6017, 34095 Montpellier Cedex 5, France. gaelle.coussot@univ-montp1.fr
Gaëlle
G
Coussot
Catherine
C
Perrin
Thomas
T
Moreau
Michel
M
Dobrijevic
Aurélie
A
Le Postollec
Odile
O
Vandenabeele-Trambouze
D000588:Amines / Q000032:analysis* / Q000737:chemistry; D001557:Benzenesulfonates / Q000032:analysis / Q000737:chemistry; D003124:Colorimetry / Q000379:methods*; D004396:Coloring Agents / Q000032:analysis / Q000737:chemistry; D010316:Particle Size; D011126:Polypropylenes / Q000138:chemical synthesis / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D013499:Surface Properties
D000588:Amines; D001557:Benzenesulfonates; D004396:Coloring Agents; D011126:Polypropylenes; D011137:Polystyrenes; C006796:brilliant blue