Carbon dots based dual-emission silica nanoparticles as ratiometric fluorescent probe for chromium speciation analysis in water samples

Abstract

A simple and effective strategy for designing a ratiometric fluorescent nanosensor was described. A carbon dots (CDs) based dual-emission nanosensor for chromium speciation analysis was developed by coating CDs on the surface of dye-doped silica nanoparticles. The fluorescence of the resulting dual-emission silica nanoparticles was quenched in acetic acid through potassium bromate (KBrO3) oxidation. Cr(VI) was able to catalyze KBrO3 oxidation, resulting in ratiometric fluorescence accelerated quenching response of the dual-emission silica nanoparticles. Several important parameters affecting the nanosensor performance, including acid type, concentrations of KBrO3, and reaction temperature and time were examined. Under the optimized conditions, the detection limit of the nanosensor towards Cr(VI) reached 1.3 ng mL−1, and pretty good linearity was obtained between 20 to 500 ng mL−1. More importantly, the sensor was found suitable for speciation analysis of both Cr(III) and Cr(VI) in different water samples with satisfactory results.

Luminescent Sol-Gel Glasses from Silicate–Citrate–(Thio)Ureate Precursors

“…Besides, it has been shown that silica gel glasses produced from silicate carboxylate precursors exhibit high PL characteristics [13]. Recent advancements in synthesis and analysis of silica/CDs composites revealed great potential of such systems in bioimaging, sensor, as well as solid-state lighting applications, and depending on the synthesis methods and the precursors used, it is possible already to achieve the PL QY from typically 7-14 up to 60% [14][15][16][17][18][19][20][21][22]. Table 2 gives the PL characteristics of some carbon-containing silica-based materials synthesized using various methods.…”

Novel single excitation dual-emission carbon dots for colorimetric and ratiometric fluorescent dual mode detection of Cu2+ and Al3+ ions

“… 18 Results showed that the addition of Cu 2+ ion could bring about obvious ratiometric fluorescence response owing to the recognition interaction from the terminal ethylenediamine groups on CDs surface. In Xiang's research works, 19,20 they found that this dual-emission nanosystem based on CDs linked silica nanoparticles could be used to build another ratiometric fluorescence sensor through the inhibition or catalyzing the oxidation process of KBrO 3 . In addition, with the help of the dispersion and crosslinking capabilities of silica layer, Liu et al obtained dual-emission nanocomposite with apparent core–shell structure via covering CDs to the external surface of nitride phosphor.…”

Luminescent materials based on organic salts pyrolyzed at the silica surface

“…In this respect, a promising direction is the formation of CDs with doped heteroatoms on the surface of oxide materials, in particular silica. Thus, recent advancements in synthesis and analysis of silica/CDs composites revealed great potential of such systems in bioimaging, sensor, as well as solid-state lightning applications, and, depending on the synthesis methods and the precursors used, it is possible already to achieve the PL QY from typically 5-14 up to 41 % [13][14][15][16][17][18][19][20]. Most of the synthetic methods are still relatively complex and costly.…”