Details

Autor(en) / Beteiligte

• Han, Bingyan
• Hu, Xixi
• Yan, Qin
• Jiang, Jingmei
• He, Gaohong

Titel

Ag-location-based color-tunable fluorescent AuAg nanoclusters for “turn-on” and “turn-off” detection of l-cysteine

Ist Teil von

• Sensors and actuators. B, Chemical, 2019-04, Vol.284, p.695-703

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •The color-tunable AuAg NCs protected by β-lactoglobulin (β-Lg) are designed by adjusting the location of Ag element.•The bimetal yellow-AuAg NCs@β-Lg AuAg NCs can change to orange-AuAg NCs@β-Lg-Ag+ with a “Ag+ shell” outside the AuAg NCs.•The yellow-AuAg NCs@β-Lg can be used for the “turn on” detection for Cys.•The orange-AuAg NCs@β-Lg-Ag+ are used for “turn off” detection for Cys. The color-tunable AuAg nanoclusters (AuAg NCs) are designed by adjusting the location of Ag element, in which β-lactoglobulin (β-Lg) serves as the capping and reducing agent. The mono-metal Au NCs emit red-fluorescent emission (red-Au NCs@β-Lg); however, the stronger metallophilic interaction between Au and Ag facilitate the smaller size, and then the bimetal AuAg NCs@β-Lg present yellow emission (yellow-AuAg NCs@β-Lg). A “Ag+ shell” outside the AuAg NCs@β-Lg cause the emission change to orange (orange-AuAg NCs@β-Lg-Ag+). This is the first time for Ag+ to tune continuously the emission wavelength of AuAg NCs. TEM proves that the size of particle has a close relationship with the fluorescence emissions. l-cysteine (Cys) stabilized the protective effect of β-Lg and shows a “turn on” effect on the fluorescence intensity of yellow-AuAg NCs@β-Lg. In contrary, the strong interaction between Cys and Ag+ destroys the protection of β-Lg to the core of yellow-AuAg NCs@β-Lg and shows a distinct “turn off” effect on the fluorescence intensity of orange-AuAg NCs@β-Lg-Ag+. The above phenomenon has been successfully applied to the detection of Cys in the Hela cells. This location-based color-tunable strategy is expected to open up a new potential to improve the performance of NCs.