Rui Feng,Xin Hu,Yuxin Ma,Liping Sun,Yaying Lv,Kyung Ho Row,Tao Zhu
PS-DVB-TiO2 modifying with amino (polyethyleneimine or polyaniline) were synthesized, and they were characterized by scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer Emmett Teller. The obtained polymers were used for purification of myricetin and quercetin from Epipremnum aureum rhizome by pipette-tip solid-phase extraction. The satisfactory extraction recoveries for the two targets (myricetin 86.39% and quercetin 83.67%) were obtained by changing different washing and eluted solvents. The result showed that the obtained modified PS-DVB exhibited high mechanical strength and special selectivity to the targets, and the proposed method was successfully applied for purifying complex samples with PT-SPE.Abbreviation PS-DVB: poly (styrene-divinylbenzene); PEI: polyethyleneimine; PANI: polyaniline; SPE: solid-phase extraction; MIP-SPE: molecularly imprinted solid-phase extraction; UAE: ultrasound-assisted extraction; MSPD: molecularly imprinted-matrix solid phase dispersion; PT-SPE: Pipette-tip solid-phase extraction; DMF: N, N-Dimethylformamide; SEM: scanning electron microscopy; TGA: thermogravimetric analysis; FT-IR: fourier transform infrared spectroscopy; BET: Brunauer Emmett Teller.
Yating Xu,Tingting Lei,Pan Zhu,Shaojing Zhao,Jiafu Xiao,Minhuan Lan
Accurate and sensitive detection of mercury ions (Hg 2+ ) and thiram is essential for food safety monitoring and environmental protection. Here, an “on-off-on” fluorescent probe based on red-emitting carbon dots (CDs) was fabricated for sequential detection of Hg 2+ and thiram. The CDs exhibited red fluorescence at λ em = 676 nm with a narrow full width at half maximum of 25 nm. Upon exposure to Hg 2+ , the fluorescence was significantly quenched due to the static quenching mechanism, achieving a limit of detection (LOD) of 25 nM. Notably, upon the addition of thiram, the quenched fluorescence of CDs was recovered due to the strong chelation between thiram and Hg 2+ , thereby enabling sensitive detection of thiram with a LOD of 4.80 nM. The approach was successfully validated using real water samples spiked with Hg 2+ and thiram. The recovery rates were between 97.16 % and 113.83 %, with relative standard deviations below 9.11 %. This study presents a simple, eco-friendly, and effective approach for the sensitive screening of trace contaminants in complex matrices.
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