Tumelo H Tabanea
Botswana International University of Science and Technology, Botswana
Title: Synthesis and optimization of a novel molecularly imprinted polymer for the selective removal of interfering hemoglobin prior to whole blood analysis
Biography
Biography: Tumelo H Tabanea
Abstract
A heavy red globular protein, hemoglobin, responsible for whole blood red pigmentation often interferes with the identification and quantification of biomarkers and toxicants/drug residues from whole blood, in fields of molecular diagnostics and forensic toxicology, respectively. The main challenge at hand has always been the direct introduction of whole blood as a sample into the analyzing instruments because of its physiological complexity and `dirty` nature. For example, the red pigment in whole blood, which is characterized as ‘dirt’, usually co-elute with the biomarkers and toxicants/drug residues and masks them from reproducible chromatographic separation prior to their final detection. It also clogs the instruments components such as the separating columns, leading to imprecise and inaccurate results during bio-assaying. To address these challenges, our lab synthesized a selective, sensitive, cheap and robust novel hemoglobin imprinted polymer (Hb-MIP) in the form of a powder, through free-radical bulk polymerization employing molecular imprinting technology (MIT), for the selective removal of interfering hemoglobin from whole blood samples prior to instrumental analysis. Following the batch rebinding experiments, the Hb-MIP powder effectively removed hemoglobin from whole blood samples as demonstrated by the UV-Vis absorbance reductions from as high as 2.50 to lower values of 0.20. It also proved to be efficient by optimally removing hemoglobin within 18 minutes. Furthermore, the powder continued to show good selectivity towards hemoglobin as demonstrated by the percentage removal efficiency of 80%, towards hemoglobin even in the presence of analogous species such as chlorophyll with negligible percentage removal efficiency of about 20%. The Hb-MIP was further compared to a commercially available clean-up material, graphitized carbon black (GCB) powder, which is pricey and not selective. The Hb-MIP powder achieved comparable selectivity in removing hemoglobin than the chlorophyll when compared to GCB which was non selective in removing the two. Thus, this preliminary work demonstrates that conventional whole blood clean-up strategies such as centrifugation, prior to whole blood analysis may be replaced by our optimal and novel clean-up strategy or our novel strategy and some conventional methods may be combined to achieve optimal clean-up of whole blood samples before molecular diagnostic and toxicology assaying. This would result in more accurate analysis and low cost of maintaining the analyzing instruments which often run into several thousand US dollars.