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Quantification of Calcium Dipicolinate in Bacillus Anthracis Spores Using a Beetroot Pigment



Paul C. DeRose, Sandra M. Da Silva, Let?a C. Gon?ves, Erick L. Bastos, R¿o A. Ando


In this proof-of-concept study, we describe the use of the main red beet pigment betanin for the detection of bacterial spores, including Bacillus anthracis. In the presence of europium(III) ions, betanin is converted to a water-soluble, non-luminescent orange 1:1 complex with a stability constant of 1.4 × 105 L mol–1. The addition of calcium dipicolinate, largely found in bacterial spores, changes the color of the aqueous solution of [Eu(Bn)+] from orange to magenta. The LOD of calcium dipicolinate is around 2.0 × 10–6 mol L–1, allowing the detection of B. anthracis and B. cereus spores submitted to thermal treatment from a calibration curve. The LOD determined for both spores, B. cereus and B. anthracis, was (1.1 ± 0.3) × 106 spores mL–1. This simple, green, fast and low cost colorimetric assay was selective for calcium dipicolinate when compared to several analogous compounds. The importance of this work relies on the potential use of betanin, a raw natural pigment, as a colorimetric sensor for biological application.
Biosensors & Bioelectronics


"B. anthracis", "B. cereus", "Betalains" , "Betanin"


DeRose, P. , Da, S. , Gon?ves, L. , Bastos, E. and Ando, R. (2013), Quantification of Calcium Dipicolinate in Bacillus Anthracis Spores Using a Beetroot Pigment, Biosensors & Bioelectronics, [online], (Accessed May 24, 2024)


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Created September 3, 2013, Updated March 21, 2017