Aggregation-Enhanced Emission of Gold Nanoclusters Induced by Serum Albumin and Its Application to Protein Detection and Fabrication of Molecular Logic Gates

Exploring aggregation-enhanced emission (AEE) of gold nanoclusters (Au NCs) is beneficial for extending their applications in sensing and molecular information processing. Herein, we present the first report of a protein-induced AEE effect of Au NCs. When human serum albumin (HSA) is mixed with glutathione-capped Au NCs under appropriate pH conditions, the Au NCs undergo extensive aggregation and exhibit significantly enhanced emission, attributed to the electrostatic and hydrophobic interactions between HSA and the NCs. Such an AEE effect is specific to serum albumin over a variety of other proteins, which facilitates the development of a facile approach for HSA determination. This sensing method displays satisfactory recoveries of 96.0-98.7% when it is applied to HSA detection in artificial urine. Moreover, the AEE effect is suited to the fabrication of AND and INHIBIT logic gates by using HSA and pH/protein-binding drug as inputs and the emission as output.