Tuberculosis (TB) is still one of the main causes of illness and death in the world and its eradication is still far from being a reality due to existing limitations in diagnostic, prevention and treatment methodologies [1,2]. In 2015, 1.8 million people died from this disease. Pyrazinamide (PZA) is the most effective drug against latent TB infection. The emergence of PZA-resistant strains represents a major public health problem, since both the first and second line of treatment include PZA [3]. Pyrazinoic acid (POA) has been shown to be a biomarker of susceptibility to PZA, which means that the absence of POA is evidence of resistance. 
Despite the evolution in recent years of TB diagnostic methods [4], a simple and effective diagnostic test, with high sensitivity and specificity, low cost and low run time, is not yet available. Nanostructured materials are a promising tool for the development of low-cost platforms for the detection and identification of such markers, since they offer the possibility of miniaturization, multi-species monitoring, and high molecular specificity. 
This work presents the fabrication of gold nanowell arrays, through gold evaporation on a nanostructured surface of anodic aluminium oxide, and their use as Raman dispersion amplifiers for POA detection. Using the nanowell arrays as substrates for surface enhanced Raman spectroscopy (SERS), spectra for different concentrations of POA in water were obtained, observing a linear dependence of 4-0.25 mM, a highly relevant range from the point of view of TB diagnosis.

References:
[1] E. L. Corbett et al., Arch. Intern. Med., 163 (2003) 1009-1021
[2] K. Bourzac, Nature, 507 (2014) S4-S7.
[3] B. R. Bloom et al., Science, 257 (1992) 1055-1064
[4] S. Wang et al., Biotechnol. Adv., 31 (2013) 438-449

SERS detection of pyrazinamide-resistant Mycobacterium tuberculosis using gold nanowells

LatinXChem

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.