A novel macrocycle acridine-based fluorescent chemosensor for selective detection of Cd2+ in Brazilian sugarcane spirit and tobacco cigarette smoke extract

A new acridine-based chemosensor (L) was prepared, characterized and investigated for quantitative detection of Cd2+ ions in ethanolic solutions. DFT and TD-DFT calculations showed that coordination of the macrocyclic sensor L to Cd2+ inhibits the photoelectron transfer (PET) mechanism, and accounts for the fluorescence enhancement of 746%, with no effect of interfering ions. Benesi-Hildebrand and Job formalisms showed the formation of a very stable 1:1 [CdL](2+) complex, with a binding constant of 1.05 x 10(9) L mol(-1). Limit of detection and limit of quantification were as low as 9.98 and 33.31 nmol L-1, respectively (R-2 = 0.996, least squares method), and a linear concentration range of 0.10-1.00 mu mol L-1. Consistency of the analytical curve, as well as repeatability, reproducibility, robustness, and reversibility was confirmed based on the determination of various parameters of merit. In addition, the sensor L was tested in recovery tests in three distinct matrices, Brazilian sugarcane spirit (also known as "cachaca" and used to prepare the famous "caipirinha" coquetel), Brazilian sake, and the tobacco cigarette mainstream smoke captured in ethanol. Analytical figures of merit showed that the chemosensor can be an attractive, easy to prepare alternative for detection of Cd2+ in ethanolic media.