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A molecularly designed imprinting method was combined with a gravimetric nanosensor for the real-time detection Cu(II) ions in aqueous solutions without using expensive laboratory devices. Thus, 1:1 and 2:1 mol-ratio-dependent coordination modes between Cu(II), N-methacyloly-L histidine methyl ester (MAH) functional monomer complexes, and their four-fold and six-fold coordinations were calculated by means of density functional theory molecular modeling. Cu(II)-MIP1 and Cu(II)-MIP2 nanoparticles were synthesized in the size range of 80-100 nm and characterized by SEM, AFM and FTIR. Cu(II)-MIP nanoparticles were then conducted to a quartz crystal microbalance sensor for the real-time detection of Cu(II) ions in aqueous solutions. The effects of initial Cu(II) concentration, selectivity, and imprinting efficiency were investigated for the optimization of the nanosensor. Linearity of 99% was obtained in the Cu(II) ion linear concentration range of 0.15-1.57 µM with high sensitivity. The LOD was obtained as 40.7 nM for Cu(II)-MIP2 nanoparticles. The selectivity and the imprinting efficiency of the QCM nanosensor were obtained significantly in the presence of competitive ion samples (Co(II), Ni(II), Zn(II), and Fe(II)). The results are promising for sensing Cu(II) ions as environmental toxicants in water by combining molecularly designed ion-imprinted nanoparticles and a gravimetric sensor.

Molecularly imprinted polymer-based surface plasmon resonance sensor prepared using silver nanoparticles was designed for the selective recognition of Penicillin G (PEN-G) antibiotic from both aqueous solution and milk sample. PEN-G imprinted sensors (NpMIPs) SPR sensor was fabricated using poly (2-hydroxyethyl methacrylate-N-methacroyl-(L)-cysteine methyl ester)-silver nanoparticles-N-methacryloyl-L-phenylalanine methyl ester polymer by embedding silver nanoparticles (AgNPs) into the polymeric film structure. In addition, a non-imprinted (NpNIPs) SPR sensor was prepared by utilizing the same polymerization recipe without addition of the PEN-G template molecule to evaluate the imprinting effect. FTIR-ATR spectrophotometer, ellipsometer, contact angle measurements were used for the characterization of NpMIPs SPR sensors. The linear concentration range of 0.01-10 ng/mL PEN-G was studied for kinetic analyses. The augmenting effect of AgNPs used to increase the surface plasmon resonance signal response was examined using polymer-based PEN-G imprinted (MIPs) sensor without the addition of AgNPs. The antibiotic amount present in milk chosen as a real sample was measured by spiking PEN-G into the milk. According to the Scatchard, Langmuir, Freundlich and Langmuir-Freundlich adsorption models, the interaction mechanism was estimated to be compatible with the Langmuir model.

Human immunoglobulin M (hIgM) antibodies are considered as hopeful tools for diseases therapy. Therefore, chromatography approaches are used to purify hIgM with a single step. In this study, we prepared a poly(hydroxyethyl methacrylate) based immunoaffinity p(HEMA-I) cryogel column by using cyanamide to immobilize antihuman immunoglobulin on the p(HEMA) cryogel for purification of hIgM in aqueous solution and artificial human plasma. The characterization of the p(HEMA) cryogel column was performed by using a scanning electron microscope (SEM), micro-computerized tomography (µ-CT), Fourier transform infrared spectroscopy (FTIR), swelling degree and macro-porosity. Further, the optimizations of various parameters were performed such as, pH, ionic strength, temperature and concentration of hIgM in aqueous solutions. In addition, the Langmuir adsorption model was supported by experimental results. Maximum adsorbed amount of hIgM corresponded to 11.1 mg/g at pH 5.75 [morpholino ethanesulfonic acid (MES buffer)]. Our results indicated that the p(HEMA-I) cryogel column can be reused at least 10 times without significant loss in adsorption capacity. As a natural source, artificial human plasma was selected for hIgM adsorption and the purity of hIgM was evaluated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)., Competing Interests: There is no conflict of interest for authors.