Gold nanoclusters as a near-infrared fluorometric nanothermometer for living cells

The authors describe the syntheses and application of glutathione-capped gold nanoclusters (AuNCs) with thermoresponsive properties. The AuNCs have excitation/emission maxima at 430/610 nm and the bright redfluorescence changes along with the temperature in the range from 0 to 90 °C which covers the normal temperature range of living cells. In the range of physiological temperatures (35-42 °C), the temperature resolution is 0.73 °C. The AuNCs display excellent colloidal stability and biocompatibility. They were used for fluorometric temperature detection and imaging of hepatic stellate cells. With such attractive features, the AuNCs are quite promising luminescence nanothermometers. Graphical abstract Schematic presentation of the fluorescence of glutathione-capped gold nanoclusters (AuNCs) as nanothermometers in living cells. The AuNCs have excitation/emission maxima at 430/610 nm and the red fluorescence changes with temperature in a wide range of 0 to 90 °C which covers the normal temperature of living cells.