Tween 80 Improves the Acid-Fast Bacilli Quantification in the Magnetic Nanoparticle-Based Colorimetric Biosensing Assay (NCBA)

Abstract

Despite its reduced sensitivity, sputum smear microscopy (SSM) remains the main diagnostic test for detecting tuberculosis in many parts of the world. A new diagnostic technique, the magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was optimized by evaluating different concentrations of glycan-functionalized magnetic nanoparticles (GMNP) and Tween 80 to improve the acid-fast bacilli (AFB) count. Comparative analysis was performed on 225 sputum smears: 30 with SSM, 107 with NCBA at different GMNP concentrations, and 88 with NCBA-Tween 80 at various concentrations and incubation times. AFB quantification was performed by adding the total number of AFB in all fields per smear and classified according to standard guidelines (scanty, 1+, 2+ and 3+). Smears by NCBA with low GMNP concentrations (≤1.5 mg/mL) showed higher AFB quantification compared to SSM. Cell enrichment of sputum samples by combining NCBA-GMNP, incubated with Tween 80 (5%) for three minutes, improved capture efficiency and increased AFB detection up to 445% over SSM. NCBA with Tween 80 offers the opportunity to improve TB diagnostics, mainly in paucibacillary cases. As this method provides biosafety with a simple and inexpensive methodology that obtains results in a short time, it might be considered as a point-of-care TB diagnostic method in regions where resources are limited.

Applications of nanomaterials as treatments and diagnostic biosensors in microbial infections

“…The combination of GMNP and Tween 80 improves the count of acid-fast bacilli, thus providing a simpler, faster and cheaper method for detecting TB. 165 For vaccine development, in addition to anthrax and TB vaccines mentioned above, NPs have also been used to develop vaccines against common pathogens such as Streptococcus pneumoniae, 161 A. baumannii, 160 Yersinia pestis, 162 and so on. For immunotherapy, since the excessive immune response may hinder the repair of lung tissue, siRNA-loaded pSiNPs were developed to silence the Irf5 gene in macrophages by RNAi, thereby preventing the excessive inflammatory response.…”

“…Nanomaterials can also be applied in disease diagnosis, vaccine development and immunotherapy. The combination of GMNP and Tween 80 improves the count of acid‐fast bacilli, thus providing a simpler, faster and cheaper method for detecting TB 165 . For vaccine development, in addition to anthrax and TB vaccines mentioned above, NPs have also been used to develop vaccines against common pathogens such as Streptococcus pneumoniae , 161 A. baumannii , 160 Yersinia pestis , 162 and so on.…”