A luminescent sensor based on in-situ formed copper nanocluster-loading terbium coordination polymer with multicolor response for identification of antibiotics

Identification of multiple antibiotics is of great interest owing to the requirement of food safety and pollution control in environment. Herein, a multicolor luminescent sensor (GT-GC) was designed based on an infinite coordination polymer (GT) formed by guanosine monophosphate (GMP) and lanthanoid ions Tb3+ as host matrix, and in-situ formed copper nanoclusters (CuNCs, GC) formed by glutathione and Cu2+ as guest species. TEM and SEM images showed that CuNCs further aggregated under the host-guest interaction. As a result, the as-prepared GT-GC not only emit characteristic luminescence of Tb3+ at 490, 544, 586 and 620 nm, but also emit the luminescence of CuNCs at 631 nm due to AIE effect. In addition, including the intrinsic luminescence of antibiotics in GT-GC at about 439 nm, the GT-GC exhibits 6-channel luminescence originated from three luminescence centers of Tb3+, CuNCs and antibiotics. In this work, 26 antibiotics were well identified based on the luminescence responses of the GT-GC and consequent linear discrimination analysis (LDA). The unknown antibiotics in real samples were also successfully identified. Due to the multi-color variation of GT-GC upon the addition of antibiotics, the visual on-site rapid detection of antibiotics was realized by a smartphone installed color recognition program.