Permeation behavior of pure gases (CO 2 , N 2 , CH 4 ) and ternary gas mixtures of CO 2 , CH 4 , and H 2 S through a poly(ester urethane urea) membrane was investigated at different pressures, temperatures, and feed compositions. Permeances of CO 2 , CH 4 , and H 2 S through the membrane were determined at temperatures of 35, 45, and 55 °C, and pressures of 10, 20, and 30 bar. Effects of temperature, pressure, and stage cut on the permeability of gases through the membrane were experimentally studied. Since the main objective of this study was to evaluate the aforesaid membrane for its ability to remove acid gas application, the measured selectivity of poly(ester urethane urea) in this study was compared with that of some other polymeric membranes at nearly the same operating conditions. Maximum selectivities of 43 and 16 were measured for H 2 S/CH 4 and CO 2 /CH 4 , respectively. Average permeances of 95 and 45 GPU for H 2 S and CO 2 were achieved, respectively.

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Cardiac troponin-I (cTnI) is a well-known biomarker for the diagnosis and control of acute myocardial infarction in clinical practice. To improve the accuracy and reliability of cTnI electrochemical immunosensors, we propose a multilayer nanostructure consisting of Fe3O4-COOH labeled anti-cTnI monoclonal antibody (Fe3O4-COOH-Ab1) and anti-cTnI polyclonal antibody (Ab2) conjugated on Au-Ag nanoparticles (NPs) decorated on a metal–organic framework (Au-Ag@ZIF-67-Ab2). In this design, Fe3O4-COOH was used for separation of cTnI in specimens and signal amplification, hierarchical porous ZIF-67 extremely enhanced the specific surface area, and Au-Ag NPs synergically promoted the conductivity and sensitivity. They were additionally employed as an immobilization platform to enhance antibody loading. Electron microscopy images indicated that Ag-Au NPs with an average diameter of 1.9 ± 0.5 nm were uniformly decorated on plate-like ZIF-67 particles (with average size of 690 nm) without any agglomeration. Several electrochemical assays were implemented to precisely evaluate the immunosensor performance. The square wave voltammetry technique exhibited the best performance with a sensitivity of 0.98 mA mL cm−2 ng−1 and a detection limit of 0.047 pg mL−1 in the linear range of 0.04 to 8 ng mL−1.

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