ABSTRACT
We developed a technique that detects Al3+ in milk/bio-samples, and reversibly applied to recognize tetracycline (TC) in milk, enhancing the fluorescence intensity without interference from other cations (Cd2+, Ni2+, Co2+, Sr2+, Mg2+, Fe3+, K+, Sm3+, Ag+, Na+, Ba2+, Cr3+, Zn2+ and Mn2+); the limit of detection (LOD) is found to be 0.00022â¯mM with r2â¯=â¯0.9439. The detection of Al3+ is tested in milk as well as in living cells (Saccharomyces cerevisiae and Debaryomyces spp.) by TC or by its quantum dots. This is consistent with the molecular orbital, revealing that the lowering of the energy of HOMO (Highly Occupied Molecular Orbital) discourages the electron transfer from HOMO of fluorophore to HOMO of excited states of Al-complex that increases the fluorescent intensity. Interestingly, carbon dots (CDs) generated from TC also recognize Al3+ as its LOD is as low as to 0.00050â¯mM with r2 of 0.9404.
