Gold nanocluster-DNase 1 hybrid materials for DNA contamination sensing

Protein encapsulated gold nanocluster (P-AuNC) synthesis was first demonstrated in 2009.[1] Initially these P-AuNCs were used as cellular imaging agents as the protein shell surrounding the AuNC made them highly biocompatible. However, recent studies have begun to show that these stabilizing proteins may also retain native biological function thus giving a dual functionality to these hybrid molecules. Here we present the synthesis of DNase 1 stabilized gold nanoclusters (DNase 1:AuNCs) with core sizes consisting either 8 or 25 atoms. The DNase 1:Au8NCs exhibit blue fluorescence whereas the DNase 1:Au₂₅NCs are red emitting. Moreover, in addition to the intense fluorescence emission; the synthesized DNase 1:AuNC hybrid retain the native functionality of the protein, allowing simultaneous detection and digestion of DNA with a detection limit of 2 μg/mL (Scheme 1). The DNase 1:AuNCs could be conveniently employed as efficient and fast sensors to augment the current inefficient and time consuming DNA contamination analysis techniques.