Photoinduced electron transfer fluorometric Hg(II) chemosensor based on a BODIPY armed with a tetrapod receptor

A second-order fluorimetric approach based on a boron dipyrromethene tetraamide derivative for Hg(ii) chemosensing in water and fish samples

“…32 The obtained limit of detection (LOD ¼ 2 ng mL À1 ) is signicantly lower than that obtained using the same BODI-PYTD chemosensor, but applying univariate calibration (LOD ¼ 5.5 ng mL À1 , ref. 18), and this is a clear demonstration of the positive effect of the multivariate calibration on the sensitivity of the analysis. 23 The relative error of prediction (REP ¼ 3%) indicates a very good precision.…”

“…Although the United States Environmental Protection Agency (US EPA) 36 has set a maximum contaminant level of Hg(II) in drinking water at 2 ng mL À1 , and a tolerance limit in surface water of 10 ng mL À1 , 37 higher concentrations can be detected (>50 ng mL À1 ) in industrial wastewaters. 18,38 As a conclusion, the LOD calculated applying the present methodology is appropriate for determining Hg(II) ions in environmental samples (surface waters and industrial wastewaters), as suggested by the US EPA, with the advantage that it was obtained by applying a simple method with a minimal sample treatment, and without using organic solvents. The above described EJCR test was applied to these samples (data not shown) and the obtained result, with the theoretically expected values of slope ¼ 1 and intercept ¼ 0 included within the corresponding ellipse, corroborates the accuracy of the method.…”

“…18 In fact, maximum uorescence is observed when the BODIPYTD and Hg 2+ react in a 1 : 2 ratio under stirring for ve minutes in the darkness, and then phosphate buffer (pH ¼ 7.50) is added in order to stabilize the uorescence response of the complex. Fig.…”

“…1) was described for the uorimetric determination of Hg(II) in environmental water samples. 18 While this particular derivative exhibits a weak uorescence emission intensity due to a deactivating photo-electron transfer (PET) effect acting over the BODIPY core, an intense uores-cence signal is detected in the presence of Hg(II). This increase in emission intensity was assigned to mercury complex formation involving the nitrogen atoms of the receptor moiety, which blocks the deactivating PET mechanism.…”

“…18 However, it is likely that real environmental and biochemical matrices will contain other uorescent constituents (organic pollutants, humic and fulvic acids, waste materials, degradation products, pharmaceuticals and their metabolites, aminoacids, proteins, etc.) which could interfere in this spectrouorimetric determination, for example by displaying overlapping spectra.…”