An SPE-assisted BODIPY fluorometric paper sensor for the highly selective and sensitive determination of Cd2+ in complex sample: rice

Abstract

By using sensing technology, the individual component analysis at trace level in complex samples remains problematic simply because of various interfering species. For example, the determination of Cd(2+) in rice is difficult due to the co-existing interfering metal cations at thousands or even millions of times higher concentrations. In this study, a heavy-metal ion sensitive BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene)-based fluorometric paper sensor with assistance of solid phase extraction (SPE) was developed for the highly selective and sensitive determination of trace Cd(2+) in rice. SPE column packed with prepared sulfonated PS-DVB microspheres was employed to enrich trace Cd(2+) and meanwhile remove most interfering heavy-metal ions in simulated complex rice sample with oxalic acid as eluent, which was theoretically selected on the basis of f values. Mn(2+), as a major coexistent heavy-metal ion, could not be easily removed by SPE, but showed little fluorescent response for BODIPY fluorometric paper sensor even in excess amounts. Combining the separation and enrichment capability of SPE column with the selectivity of BODIPY-based fluorometric paper sensor, we were able to detect trace Cd(2+) in complex samples. The response of fluorometric paper sensor was linearly related with Cd(2+) concentrations in the range of 0.5-4 μM, with a detection limit of 0.5 μM. Twelve real rice samples spiked with Cd(2+) were analysed using this method and the results are in good agreement with ICP-MS measurements.

Determination of Cadmium in Brown Rice Samples by Fluorescence Spectroscopy Using a Fluoroionophore after Purification of Cadmium by Anion Exchange Resin

“…The LOD and LOQ values were estimated to be 3.8 μg-Cd/L-solution (0.03 μM) and 12.7 μg-Cd/L-solution (0.11 μM), respectively. These values were relatively low compared with those of simple analyses previously reported [ 18 , 20 ]. Furthermore, a dynamic range of BDP-TPY was investigated.…”

“…Because no indicator has perfect selectivity towards the target analyte, samples must be purified before determining the Cd content. Zhang et al have determined the Cd 2+ content in rice samples using a solid phase extraction (SPE)-assisted fluorometric paper sensor [ 20 ]. They purified and preconcentrated the Cd 2+ using SPE then determined its content using a fluoroionophore immobilized on the test paper.…”

Iodine-mediated etching of gold nanorods for plasmonic sensing of dissolved oxygen and salt iodine

“…Till now, analytical methods for determination of ions and biomolecules have attracted wide concern in environmental and biological analysis. [1][2][3][4][5][6][7] Because of the simplicity of the colorimetric method, gold nanoparticles (AuNPs) are now widely employed in colorimetric plasmonic assays based on their strong localized surface plasmon resonance (LSPR) extinction in the visible light region and distance-dependent optical property. 8,9 To date, AuNPs have been used for sensitive detection of various targets, including oligonucleotides, 10,11 proteins, 12,13 metal ions, [14][15][16] anions 17,18 and some small molecules.…”

Preconcentration of ultra-trace Cu(ii) and Cd(ii) using SPE based on an alizarin complexone modified silica gel with detection using FAAS and determination of ultra-trace Cu(ii) by the naked eye

“…16 In addition, the active hydrogen atoms of the silanol groups of silica gel have the ability to react with agents containing organosilyl functions to give some organic nature to the silica gel. Silica gel immobilized with various organic compounds such as thioacetamide, 17 alizarin violet, 18 diaminobenzidine, 19 gallic acid 20 for metal ion removal, extraction, separation and preconcentration from different matrices, have been reported. The alizarin complexone (AC) molecule provides a four coordinate chelation environment with two acetic acid groups and two vicinal hydroxyl groups, 21 and has been used to chelate many metal ions for chemical analysis.…”