Modulating Electrical Double Layers: Facile Approach for Promoting Noncovalent Interactions between Boron Nitride Nanosheets and Gold Nanoparticles

Electrical double layer (EDL) plays a crucial role in colloidal chemistry, which can be modified by changing the pH and ionic strength of a solution. Even though EDL is well-recognized, there are limited studies exploring interactions between two-dimensional (2D) and zero-dimensional nanoparticles. Herein, we demonstrate a simple pH-based approach to control the EDL of boron nitride nanosheets (BNNSs) and gold nanoparticles (AuNPs) that plays a crucial role in their interaction, displaying a one-way gate effect. We observed that as the EDL decreases, AuNPs can come into closer interaction with BNNSs, and this also resulted in a deceleration of the aggregation process of AuNPs when functionalized with l-cysteine. This work provides a fundamental understanding of how modulation of the EDL of 2D nanomaterials can be achieved through functionalizing strategies.