Synthesis of a new bimetallic Re(I)–NCS–Pt(II) complex as chemodosimetric ensemble for the selective detection of mercapto-containing pesticides

Detection of mercapto-containing pesticides plays a crucial role in food and water safety. A new Re(I)–NCS–Pt(II) complex, [Re(4,4′-di-tert-butyl-2,2′-bipyridine)(CO)3(NCS)]–[Pt(DMSO)(Cl)2] (1), was synthesized and characterized. The synthetic procedure, characterization results, and photophysical data for 1 are reported in this paper. Solvated complex 1 demonstrated luminescent chemodosimetric selectivity for phorate, demeton, and aldicarb (three common mercapto-containing pesticides) with method detection limits (MDLs) of 1.00, 2.87, and 2.08 ppm, respectively. The binding constants (log K) of 1 toward them were in the 3.24–3.44 range. The analyte selectivity of the complex was found to be dependent on the bridging linkage (C≡N and N═C═S) between the Re(I) and Pt(II) centers. The solid-supported dosimetric device 1 was fabricated by blending complex 1 with Al2O3 and poly(vinyl chloride) (PVC) powder. The MDLs of the device toward the mercapto-containing pesticides were 0.48–0.60 ppm. The device was applicable to pesticides in real water bodies such as taps, rivers, lakes, and underground water bodies with excellent recoveries and relative standard deviations of 76.2–108.0% and 2.9–6.7%, respectively. Its spectrofluorimetric changes could be analyzed by naked eye within 20 min with a linear luminometric response toward increases in the phorate concentration (0–8.0 ppm) with R = 0.999. Copyright © 2015 American Chemical Society.