A Eu3+-inspired fluorescent carbon nanodot probe for the sensitive visualization of anthrax biomarker by integrating EDTA chelation.
The rapid and sensitive visualization of 2,6-dipicolinic acid (DPA, a unique anthrax biomarker) is essential to prevent anthrax disease or biological terrorist attack. In this study, a Eu3+-labeled ethylenediaminetetraacetic acid loaded hyperbranched polyethyleneimine carbon nanodot (hPEI-CD-EDTA-Eu3+) nanoprobe has been proposed for the ratiometric DPA detection. The sensing mechanism is based on the rapid DPA-Eu3+ chelation within 30 s and subsequent enhanced fluorescence emission through the antenna effect. With the introduction of EDTA chelating unit, the resulted fluorescence of Eu3+-complex is greatly enhanced, which endows sensitive DPA perception. By employing hPEI-CD as the internal reference, ratiometric DPA sensing is realized with a good linearity in the concentration range from 1.0 to 100 nM, with a limit of detection of 190 pM (S/N = 3). The specific chelation affinity between Eu3+ and DPA provides satisfying selectivity over other amino acids and ions. Using nanoprobe-loaded polyvinylidene fluoride paper as the analytical device, point-of-care DPA visualization is achieved. Furthermore, the practical application of designed paper device is validated by the visual detection of metabolic DPA-release from Bacillus subtilis spores.
['Yang|Hongwei|H|', 'Lu|Fengniu|F|', 'Zhan|Xingxiao|X|', 'Tian|Mingce|M|', 'Yuan|Zhiqin|Z|', 'Lu|Chao|C|']
D001412:Bacillus subtilis D015415:Biomarkers D002244:Carbon D004492:Edetic Acid D005063:Europium D005456:Fluorescent Dyes D006801:Humans D057230:Limit of Detection D049329:Nanostructures D010848:Picolinic Acids D011094:Polyethyleneimine
Carbon nanodot Visualization 2,6-Dipicolinic acid Bacillus anthracis Fluorimetric sensing