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.