A dual-ionic liquid microemulsion system for the selective isolation of hemoglobin

Abstract

A novel dual-ionic liquid (IL) microemulsion system is developed with IL 1-decyl-3-methylimidazolium bromide (DmimBr) as the surfactant and IL 1-butyl-3-methylimidazolium hexaflourophosphate (BmimPF 6 ) as a substitute for organic solvent. The phase diagram of this dual-IL microemulsion system clearly shows the formation of a single phase within a wide range of BmimPF 6 (1.76-98.3%, wt) and in the presence of an appropriate amount of DmimBr and water. The microemulsion is characterized by means of FT-IR spectra, dynamic light scattering and molecular probe. The dual-IL microemulsion system has been demonstrated to be effective for the extraction of proteins, and exhibited an obvious improvement in extraction efficiency for hemoglobin in comparison with pure BmimPF 6 . When 100 mL microemulsion is used to extract 100 mg mL À1 of proteins in an equal volume of sample solution, high selective extraction of hemoglobin (Hb) has been observed at pH 5. This might be attributed to the coordination interaction between the heme group of Hb and the imidazolium cationic moiety in the ionic liquids. Hb transferred into the microemulsion can be readily recovered by back extraction with Britton-Robinson buffer at pH 12, giving rise to a recovery of 55.6%. The dual-IL microemulsion system is practically applied to the isolation of Hb from human whole blood and the SDS-PAGE indicates that hemoglobin has been selectively isolated from human blood in the presence of co-existing protein species.

TiO2 nanoparticle modified organ-like Ti3C2 MXene nanocomposite encapsulating hemoglobin for a mediator-free biosensor with excellent performances

“…S7(A)) are almost the same as that obtained for native Hb (1657 and 1542cm −1 , Fig. S7(B)), and are essentially consistent with the reported value of native Hb (Ma and Tian, 2010;Mao et al, 2014;Sun et al, 2013;Sun et al, 2009). The similarities of the two spectra demonstrated that Hb retained the essential features of its native secondary structure on Nafion/Hb/TiO 2 -Ti 3 C 2 composite film.…”

“…This reveals that TiO 2 -Ti 3 C 2 nanocomposite has biocompatibility and did not suffer significant protein denaturation. FTIR spectroscopy is also an effective means to explore the secondary structure of Hb entrapped in Nafion/Hb/TiO 2 -Ti 3 C 2 composite film (storage at 4 °C for 60 days) (Liu et al, 2015a;Lu et al, 2008;Mao et al, 2014;Sun et al, 2014a). The shapes of amide I and amide II bands of protein provide detailed information on the secondary structure of polypeptide chain (Kauppinen et al, 1981).…”

Ionic-Liquid-Mediated Extraction and Separation Processes for Bioactive Compounds: Past, Present, and Future Trends

“…The IL [C 10 C 1 im]Br was used as the surfactant and the IL [C 4 C 1 im][PF 6 ] as substitute for the organic solvent. 277 The dual-IL microemulsion system proved to be more effective for the extraction of proteins in comparison with the isolated [C 4 C 1 im][PF 6 ] system. Lower pH values were found to be favorable for the selective extraction of Hb, as a result of the coordination interaction between the heme group of Hb and the imidazolium cationic moiety, 277 and in agreement with the results of Shu et al 276 By adding an alkaline Britton–Robinson buffer at pH 12, the authors also performed the back-extraction of the protein with a recovery yield of 55.6%.…”

“… 277 The dual-IL microemulsion system proved to be more effective for the extraction of proteins in comparison with the isolated [C 4 C 1 im][PF 6 ] system. Lower pH values were found to be favorable for the selective extraction of Hb, as a result of the coordination interaction between the heme group of Hb and the imidazolium cationic moiety, 277 and in agreement with the results of Shu et al 276 By adding an alkaline Britton–Robinson buffer at pH 12, the authors also performed the back-extraction of the protein with a recovery yield of 55.6%. 277 In summary, and although only briefly investigated, both works 273 , 274 demonstrated the potential applicability of IL-based microemulsions for the isolation of Hb from human whole blood samples, while opening the path to explore this type of system for the purification of other proteins from real and complex matrices.…”

Layer-by-layer encapsulated nano-emulsion of ionic liquid loaded with functional material for extraction of Cd2+ ions from aqueous solutions

“…One of the ways to increase the extraction efficiency is to increase the contact area between the ionic liquid and a solution containing ions that need to be extracted. This can be accomplished by creating a nano-emulsion of the ionic liquid, which greatly increases its surface area, minimising the amount of material required for extraction [9][10][11]. Moreover, nano-emulsions are kinetically stable, and their small size makes them resistant to sedimentation or creaming [12], providing greater control over the extraction process, and allowing for greater storage times.…”