Sodium Lauryl Sulfate-Conjugated Cationic Gemini-Surfactant-Capped Gold Nanoparticles as Model System for Biomolecule Recognition

Surfactant-based nanostructures are promising materials for designing novel colorimetric biosensors based on aggregation/disaggregation phenomena. In this work, a sensor the plasmonic shift of surfactant-capped gold nanoparticles via disaggregation mechanism was developed. To perform this, optimum SDS concentration firstly determined in order to form Au@16-s-16/SDS complex aggregates with well-defined SPR band blue region. Once optimal Au@16-s-16 aggregation established, sensing method depended nature electrostatic charge biopolymer studied where both strength biopolymer/SDS and biopolymer/Au@16-s-16 interactions cationic play key role processes. As result, an instantaneous color change from red gradually observed increasing concentrations. The response immediate, avoiding problems derived time lapse, highly dependent addition reagents, detection limit nanomolar picomolar range DNA Lysozyme sensing, respectively. This behavior can be correlated formation different stabilized Au@16-s-16/biopolymer/SDS complexes, which particular conformation enhances distance between among complexes.