Xylenol orange-modified CdTe quantum dots as a fluorescent/colorimetric dual-modal probe for anthrax biomarker based on competitive coordination

Talanta. 2023 May 13;261:124664. doi: 10.1016/j.talanta.2023.124664. Online ahead of print.ABSTRACTBacillus anthracis spores can make humans infected with vicious anthrax, so it is significant to detect their biomarker 2,6-pyridinedicarboxylic acid (DPA). The development of dual-modal methods for DPA detection that are more flexible in practical applications remains a challenge. Herein, colorimetric xylenol orange (XO) was modified on fluorescent CdTe quantum dots (QDs) for dual-modal detection of DPA through competitive coordination. After the binding of XO on CdTe QDs via coordination with Cd2+, CdTe QDs displayed quenched red fluorescence and the bound XO was presented as red color. The competitive coordination of DPA with Cd2+ made XO released from CdTe QDs, causing the enhanced red fluorescence of CdTe QDs and the yellow color of free XO. On this basis, DPA was rapidly (1 min) quantified through fluorescent and colorimetric modes within the ranges of 0.1-5 μM and 0.5-40 μM, respectively. The detection limits for DPA were calculated as low as 42 nM and 240 nM, respectively assigned to fluorescent and colorimetric modes. The level of urinary DPA was further measured. Satisfactory relative standard deviations (fluorescent mode: 0.1%-10.2%, colorimetric mode: 0.8%-1.8%) and spiked recoveries (fluorescent mode: 100.0%-115.0%, colorimetric mode: 86.0%-96.6%) were obtained.PMID:37209586 | DOI:10.1016/j.talanta.2023.124664

Source: Talanta - May 20, 2023 Category: Chemistry Authors: Yatian Cao Xiaolong Gong Le Li Huihui Li Xuanming Zhang Dong-Yu Guo Fuxiang Wang Qinhe Pan Source Type: research