Quantitative surface-enhanced Raman spectroscopy of dipicolinic acid - towards rapid anthrax endospore detection
Data(s) |
01/04/2005
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Resumo |
Dipicolinic acid (DPA) is an excellent marker compound for bacterial spores, including those of Bacillus anthracis ( anthrax). Surface-enhanced Raman spectroscopy (SERS) potentially has the sensitivity and discrimination needed for trace DPA analysis, but mixing DPA solutions with citrate-reduced silver colloid only yielded measurable SERS spectra at much higher (> 80 ppm) concentrations than would be desirable for anthrax detection. Aggregation of the colloid with halide salts eliminated even these small DPA bands but aggregation with Na2SO4(aq) resulted in a remarkable increase in the DPA signals. With sulfate aggregation even 1 ppm solutions gave detectable signals with 10 s accumulation times, which is in the sensitivity range required. Addition of CNS- as an internal standard allowed quantitative DPA analysis, plotting the intensity of the strong DPA 1010 cm(-1) band (normalised to the ca. 2120 cm(-1) CNS- band) against DPA concentration gave a linear calibration (R-2 = 0.986) over the range 0 - 50 ppm DPA. The inclusion of thiocyanate also allows false negatives due to accidental deactivation of the enhancing medium to be detected. |
Identificador |
http://dx.doi.org/10.1039/b415290e http://www.scopus.com/inward/record.url?scp=17144401843&partnerID=8YFLogxK |
Idioma(s) |
eng |
Direitos |
info:eu-repo/semantics/restrictedAccess |
Fonte |
Bell , S , Mackle , J N & Sirimuthu , N M S 2005 , ' Quantitative surface-enhanced Raman spectroscopy of dipicolinic acid - towards rapid anthrax endospore detection ' Analyst , vol 130 , no. 4 , pp. 545-549 . DOI: 10.1039/b415290e |
Palavras-Chave | #/dk/atira/pure/subjectarea/asjc/1600/1602 #Analytical Chemistry |
Tipo |
article |