Dual-emission CdTe quantum dot@ZIF-365 ratiometric fluorescent sensor and application for highly sensitive detection of l-histidine and Cu2.

l-histidine acts as a semi-essential amino acid, which is medically used in the treatment of gastric ulcer, anemia, allergies. However, the overuse of l-histidine will result in terrible damage to heart disease, slow growth of animals and water pollution in the environment. In addition, Cu2+ pollution is common environmental pollution in the industry. It has the characteristics of high accumulation, migration, and persistence. Given this, through the post-synthesis strategy, CdTe quantum dots (QDs) were the first time to introduce into zeolitic imidazolate framework-ZIF-365 to synthesis dual-emission hybrid material CdTe@ZIF-365 with high quantum yield. TEM mappings and N2 absorption tests are applied to confirm the combination mode between CdTe quantum dots and ZIF-365. It should be noted that CdTe@ZIF-365 can be successfully utilized as a bi-functional ratiometric sensor for highly sensitive discrimination of l-histidine and Cu2+. Firstly, CdTe@ZIF-365 is applied to a fluorescent ratiometric sensor for Cu2+ with high sensitivity (the Ksv value is 2.7417✕107 [M-1]) and selectivity in the mixed cation ions' solution. On the other hand, CdTe@ZIF-365 also behaved as the first example for an excellent ratiometric fluorescent senor for l-histidine with high sensitivity (the Ksv value is 6.0507✕108 [M-1]) and selectivity in the mixed amino acids' solutions.