Novel bimetallic gold-silver nanoclusters with "Synergy"-enhanced fluorescence for cyanide sensing, cell imaging and temperature sensing.

We herein opened up a facile and green strategy for the fabrication of bright orange-fluorescent gold-silver nanoclusters (AuAgNCs@ew, GSNCs) by a one-pot synthesis at a vital molar ratio of Au/Ag precursors in the egg white protein matrix using microwave-assisted method. The prepared GSNCs exhibited enhanced fluorescence with fluorescent quantum yield of 5.4%, which is dependent on gold and silver synergies. Due to the advantageous superiority of low-toxicity, excellent stability and satisfactory fluorescence, the as-prepared GSNCs has been successfully used in cell imaging and temperature sensing. More strikingly, the GSNCs emerged strong response to CN with rapid, selective, and ultrasensitive characteristics. The detection limit was approximately 138nM, which is nearly 20 times lower than the maximum level (2700nM) of CN in drinking water set up by the World Health Organization (WHO). In addition, the as-prepared GSNCs could be applied to detecting real samples with minimum interference. Our findings showed that this new GSNCs probe is eco-friendly and large-scale development for potential applications including the detection of environmental pollution and bioimaging.