Turn “on-off” fluorometric probe based on Sm3+ ions activated gold nanoclusters for tetracycline determination in food samples

A turn “on-off” fluorometric probe with good sensitivity and selectivity based on glutathione (GSH) fabricated gold nanoclusters (AuNCs) was developed for the determination of tetracycline (TC) in food samples in this work. Samarium ions (Sm 3+ ) were used to aggregate the GSH-AuNCs by aggregation induced emission enhancement (AIEE), as a result fluorescence (FL) of GSH-AuNCs was turned on. The Sm 3+ induced AIEE of AuNCs have eco-friendly and “green synthesis” features. Using TC, the FL of GSH-AuNCs-Sm 3+ was turned off due to the strong interaction between Sm 3+ and TC through dynamic quenching. The reasonable quantum yield (Q.Y) of GSH-AuNCs obtained using AIEE of Sm 3+ ions was 5.3 %. The linear range of this probe was 1 – 20 µM with the lowest limit of detection (LOD) of 0.33 µM. This probe showed recoveries of 90.4–105 % in honey and milk samples. The GSH-AuNCs-Sm 3+ is a good choice for sensing hazards in food products. Schematic explanation of the probe GSH-AuNCs-Sm 3+ for the determination of TC. • Glutathione protected gold nanoclusters based on AIEE behavior induced by Sm 3+ ions were prepared with Q.Y of 5.33 %. • The developed probe has lower limit of detection of 0.33 µM. • The AIEE of GSH-AuNCs triggered by Sm 3+ ions have concept of “green synthesis” and eco-friendly nature. • The probe GSH-AuNCs-Sm 3+ has good selectivity, sensitivity and interference tolerance ability. • The validity of probe was analyzed in samples of milk and honey with excellent recoveries of 90.4 % – 105 %.