Hemoglobin Adsorption/Desorption Studies of New Generation Stimuli Responsive Polyacrylic Acid-Cu2+ Hybrid Nanoflowers (PAA@Cu2+ hNFs).

In our study, pH-responsive poly(acrylic acid)-Cu2+ hybrid nanoflowers (PAA@Cu2+ hNFs) were fabricated by using poly(acrylic acid) and Cu2+ ions in phosphate-buffered saline solution (PBS). For comparison, pure copper phosphate nanoflowers (Cu NFs) were fabricated. Synthesized PAA@Cu2+ hNFs and Cu NFs were characterized using SEM, EDX, XRD, FTIR, BET, zeta potential, and DLS measurements. Within the pH range of 6-9, PAA@Cu2 + hNFs exhibit a spherical, flower-like porous morphology, with the pH 9 sample showing a more compact, uniform structure and more homogeneous interpetal pores than those at other pH values. Then, hemoglobin (Hb) adsorption studies were also performed using PAA@Cu2+ hNFs and Cu NFs across various parameters, including pH, Hb concentration, ionic strength, temperature, and time. At pH 7, the highest Hb adsorption capacities of PAA@Cu2+ hNFs and Cu NFs were calculated as 961.98 and 94.23 mg/g, respectively. The desorption studies of Hb from the synthesized nanoflowers were performed in an acetate buffer solution including NaCl. The desorption yields of Hb for PAA@Cu2+ hNFs and Cu NFs were calculated as 96.1% and 95.8%, respectively. Then, the reusability of the synthesized nanoflowers for Hb adsorption was evaluated over five cycles. These results suggest that PAA@Cu2 + hNFs are suitable for Hb separation.