RESUMO
The development of adsorption technology and the processing of radiation have both been influenced by chitosan adsorbent (γ-chitosan), a raw material with unique features. The goal of the current work was to improve the synthesis of Fe-SBA-15 utilizing chitosan that has undergone gamma radiation (Fe-γ-CS-SBA-15) in order to investigate the removal of methylene blue dye in a single hydrothermal procedure. High-resolution transmission electron microscopy (HRTEM), High angle annular dark field scanning transmission electron microscopy (HAADF-STEM), small- and wide-angle X-ray powder diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR) and Energydispersive X-ray spectroscopy (EDS) were used to characterize γ-CS-SBA-15 that had been exposed to Fe. By using N2-physisorption (BET, BJH), the structure of Fe-γ-CS-SBA-15 was investigated. The study parameters also included the effect of solution pH, adsorbent dose and contact time on the methylene blue adsorption. The elimination efficiency of the methylene blue dye was compiled using a UV-VIS spectrophotometer. The results of the characterization show that the Fe-γ-CS-SBA-15 has a substantial pore volume of 504 m2 g-1 and a surface area of 0.88 cm3 g-1. Furthermore, the maximum adsorption capacity (Qmax) of the methylene blue is 176.70 mg/g. The γ-CS can make SBA-15 operate better. It proves that the distribution of Fe and chitosan (the C and N components) in SBA-15 channels is uniform.
RESUMO
BACKGROUND: Septicemic melioidosis caused by Burkholderia pseudomallei is a serious cause of morbidity and mortality. An effective, rapid and simple diagnostic method is required for detection of B. pseudomallei infection. OBJECTIVE: To develop immunomagnetic beads (IMB) coupled with ELISA (IMB-ELISA) for detection of B. pseudomallei in blood samples of patients with suspected melioidosis. METHODS: For separation of B. pseudomallei from buffer, blood samples and hemoculture, 200 nm immunomagnetic beads (IMBs) coated with 4B11 monoclonal antibody (4B11-IMBs) against exopolysaccharide antigens were used. The detection was done by an ELISA based biotin-streptavidin system. The sensitivity and specificity were evaluated. RESULTS: 4B11-IMBs (100 µg) were successfully developed and used for detection of B. pseudomallei in 1 ml samples. Transmission electron microscopy (TEM) imaging demonstrated B. pseudomallei was captured by 4B11-IMBs. The IMBs showed high capture efficiency (98%) with B. pseudomallei in buffer. The IMB-ELISA assay was highly specific for B. pseudomallei. It showed no cross-reactions with other bacteria, except B. mallei. The limits of the B. pseudomallei assay detection for detecting B. pseudomallei in either buffer solution or blood was 102 CFU/ml. The IMB-ELISA detection sensitivity in blood samples was 44.5%. Although it did not give the highest sensitivity, it was useful for detection with hemoculture that was faster than conventional methods. CONCLUSION: This study suggests the IMB-ELISA assay offers a simple and highly specific method with a turnaround time of 6 h for detection of B. pseudomallei. The developed assay can be applied in hospitals for surveillance of B. pseudomallei.
