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In this study, copper (II) ion (Cu+2) imprinted poly(hydroxyethyl methacrylate-N-metacryloyl-(L)-cysteine methyl ester [PHEMAC-Cu+2] nanoparticles were synthesized by two-phase mini-emulsion polymerization method and applied to the SPR sensor chip surface for the selective determination of the Cu+2 ions in both aqueous solution, Cu+2-spiked artificial urine and physiological serum samples to investigate the effects of metabolite residues during the analysis. The non-imprinted [PHEMAC] nanoparticles were synthesized by applying the same procedure for the [PHEMAC-Cu+2] nanoparticle synthesis except the addition of Cu+2 ions as a control experiment to evaluate the selectivity of the [PHEMAC-Cu+2] nanoparticles. Roughness differences between [PHEMAC-Cu+2] and [PHEMAC] nanoparticles showed that the imprinting process of Cu+2 ions was performed successfully. [PHEMAC-Cu+2] and [PHEMAC] SPR biosensors prepared by attaching nanoparticles onto the surface of sensor chips, were characterized by atomic force microscope, ellipsometer, contact angle measurements. Langmuir adsorption model was found the most applicable model for this affinity system. Results showed that Cu+2 affinity regions on the surface of [PHEMAC-Cu+2] SPR biosensor were homogeneously distributed and have a monolayer structure. Having the high imprinting efficiency with the imprinting factor of 4.74, the [PHEMAC-Cu+2] SPR biosensor was found to show more selectivity towards the target Cu+2 than the non-imprinted [PHEMAC] SPR biosensor. The selectivity studies of [PHEMAC-Cu+2] SPR biosensors for Cu+2 detection were investigated by using Zn+2 and Ni+2 solutions selected as competitor molecules. The results of intraday and interday precision studies were carried out to ascertain the reproducibility of the proposed method and reported as percent relative standard deviation (%RSD) value.

The ability to detect catecholamines (CAs) and their metabolites is vital to understand the mechanism behind the neuronal diseases. Neurochemistry aims to provide an improved pharmacological, molecular and physiological understanding of complex brain chemistries by analytical techniques. Capillary electrophoresis (CE) is one such analytical technique that enables the study of various chemical species ranging from amino acids and peptides to natural products and drugs. CE can easily adapt the changes in research focus and in recent years remains an applicable technique for investigating neuroscience and single cell neurobiology. The prepared phenylalanine-based hydrophobic monolithic column, Polymethacryloyl-L-phenylalanine [PMAPA], was used as a stationary phase in capillary electrochromatography to separate CAs that are similar in size and shape to each other including dopamine (DA) and norepinephrine (NE) via hydrophobic interactions. Separation carried out in a short period of 17 min was performed with the electrophoretic mobility of 5.54 × 10−6 m2 V−1 s−1 and 7.60 × 10−6 m2 V−1 s−1 for DA and NE, respectively, at pH 7.0, 65% acetonitrile ratio with 100 mbar applied pressure by the developed hydrophobic monolithic column without needing any extra process such as imprinting or spacer arms to immobilize ligands used in separation.

A dopamine-imprinted monolithic column was prepared and used in capillary electrochromatography as stationary phase for the first time. Dopamine was selectively separated from aqueous solution containing the competitor molecule norepinephrine, which is similar in size and shape to the template molecule. Morphology of the dopamine-imprinted column was observed by scanning electron microscopy. The influence of the organic solvent content of mobile phase, applied pressure and pH of the mobile phase on the recognition of dopamine by the imprinted monolithic column has been evaluated, and the imprinting effect in the dopamine-imprinted monolithic polymer was verified. Developed dopamine-imprinted monolithic column resulted in excellent separation of dopamine from structurally related competitor molecule, norepinephrine. Separation was achieved in a short period of 10 min, with the electrophoretic mobility of 5.81x10(-5)m(2)V(-1)s(-1) at pH 5.0 and 500mbar pressure.

Pesticides have been utilized in agriculture for decades. However, their widespread use has increased multiple concerns due to their known and suspected toxicities on long-term human health risks in scientific and industrial communities. Thus, detecting pesticides will have a great impact on their management, as well as improve their toxicity effects over humans. Here, we fabricate molecularly imprinted nanofilms and integrate them with surface plasmon resonance (SPR) sensors for sensitive, selective, fast and real-time detection of multiple pesticides, including cyanazine (SNZ), simazine (SMZ) and atrazine (ATZ). The molecularly imprinted nanofilms onto the SPR gold surfaces are prepared via UV polymerization reactions, which consist of N-methacryloyl-L-phenylalanine methyl ester (MAPA) as a functional monomer, 1-vinylimidazole (VIM) as a co-monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The real-time measurements on SPR sensor provide a detection range from 0.10 to 6.64 nM, as well as denote a limit of detection (LOD) values of 0.095, 0.031 and 0.091 nM for SNZ, SMZ and ATZ, respectively. Furthermore, we perform selectivity test, where SNZ, SMZ and ATZ are examined as competitor agents. Overall, the pesticide imprinted SPR sensors have been found to be highly selective and sensitive. These SPR sensors also hold great potential to be used an alternative method for the existing pesticide monitoring approaches due to their reusability, fast response, and easy-to-use properties, as well as can be tailored to detect and real-time monitor of other pesticides. (C) 2016 Elsevier B.V. All rights reserved.

WOS:000400822900239 PubMed: 28422082 Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

Herein, we have focused on the preparation of triazinic pesticide imprinted SPR nanosensors for detection of herbicides. Triazinic pesticides are weedkillers that are related with possible carcinogenic effects, birth defects, and menstrual problems when uptake by humans. Although there are restrictions and bans on their use in some countries they are still one of the most widely used pesticides in the world. The development of rapid, sensitive, and inexpensive diagnosis tools for environmental and biological monitoring is currently a research area of great interest. Surface plasmon resonance (SPR) nanosensors have been used widely for the detection of triazinic pesticides because of their simplicity, lack of requirement for labeling and ease of miniaturization, low cost, high specificity and sensitivity, and real-time measurement. Molecularly imprinted polymers that have molecular recognition talent, are easy to prepare, less expensive, stable, and can be manufactured with good reproducibility, are used for the creation of biorecognitive surfaces on the SPR nanosensors. Herein, we have focused on the production of triazinic pesticide-imprinted SPR nanosensors.

WOS: 000407478900004, PubMed: 28322473, Diagnostic biomarkers such as proteins and enzymes are generally hard to detect because of the low abundance in biological fluids. To solve this problem, the advantages of surface plasmon resonance (SPR) and nanomaterial technologies have been combined. The SPR sensors are easy to prepare, no requirement of labelling and can be detected in real time. In addition, they have high specificity and sensitivity with low cost. The nanomaterials have also crucial functions such as efficiency improvement, selectivity, and sensitivity of the detection systems. In this report, an SPR-based sensor is developed to detect lysozyme with hydrophobic poly (N-methacryloyl-(L)-phenylalanine) (PMAPA) nanoparticles. The SPR sensor was first characterized by attenuated total reflection-Fourier transform infrared, atomic force microscope, and water contact angle measurements and performed with aqueous lysozyme solutions. Various concentrations of lysozyme solution were used to calculate kinetic and affinity coefficients. The equilibrium and adsorption isotherm models of interactions between lysozyme solutions and SPR sensor were determined and the maximum reflection, association, and dissociation constants were calculated by Langmuir model as 4.87, 0.019nM(-1), and 54nM, respectively. The selectivity studies of SPR sensor were investigated with competitive agents, hemoglobin, and myoglobin. Also, the SPR sensor was used four times in adsorption/desorption/recovery cycles and results showed that, the combination of optical SPR sensor with hydrophobic ionizable PMAPA nanoparticles in one mode enabled the detection of lysozyme molecule with high accuracy, good sensivity, real-time, label-free, and a low-detection limit of 0.66nM from lysozyme solutions. Lysozyme detection in a real sample was performed by using chicken egg white to evaluate interfering molecules present in the medium.

The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]-Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50,100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]-Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). (C) 2016 Elsevier B.V. All rights reserved.

We have synthesized PVA/PEI monolithic cryogel columns chelated with Cu2+ ions as a model adsorbent, which is capable of binding haemoglobin (Hb) from human blood. The goal of this study is to perform the depletion of Hb via a single and easy process to be useful in proteomic studies. PVA/PEI-Cu2+ cryogel columns were subjected to adsorption studies of Hb from both aqueous solution and human plasma to evaluate the extent of interaction between cryogel columns and Hb. The effects of experimental parameters, such as pH, Hb equilibrium concentration, adsorption time, temperature, and ionic strength, on Hb adsorption capacity were investigated.

WOS: 000376136500005, PubMed: 26772759, In this study, we aimed to prepare the metal chelate affinity cryogels for the hemoglobin (Hb) depletion. Poly(2-hydroxyethyl methacrylate) (PHEMA) cryogels were selected as base matrix because of their blood compatibility, osmotic, chemical, and mechanical stability. Cryogels are also useful when working with the viscous samples such as blood, because of their interconnected macroporous structure. Iminodiacetic acid (IDA), the chelating agent, was covalently coupled with PHEMA cryogels after activation with the epichlorohydrin and then the Ni(II) ions were chelated to the IDA-bound cryogels. The depletion of the Hb from hemolysate was shown by SDS-PAGE.

Surface plasmon resonance (SPR) sensors have been used for detection of various biomolecules because of their simplicity, high specificity and sensitivity, real-time detection, low cost, and no requirement of labeling. Recently, molecularly imprinted polymers that are easy to prepare, less expensive, stable, have talent for molecular recognition and also are used for creation selective binding sites for target molecule on the SPR sensors. Here, we show that preparation of cyclic citrullinated peptide antibody (anti-CCP) imprinted SPR sensor to detect CCP antibodies. For this purpose, anti-CCP/AAm pre-complex was synthesized by interacting acrylamide (AAm) monomer with anti-CCP. Then, anti-CCP imprinted (anti-CCP/PAAm) SPR sensor was obtained by reacting with anti-CCP/AAm pre-complex in the presence of the crosslinker, and initiator/activator pair. Besides this, non-imprinted (PAAm) SPR sensor was also prepared without using anti-CCP template. The SPR sensors were characterized and then adsorption-desorption studies were performed with pH 7.0 phosphate buffer (10mM) and acetic acid (10%) with Tween 20 (1%) in pH 7.0 phosphate buffer. Selectivitiy of sensors was investigated by using immunoglobulin M (IgM) and bovine serum albumin (BSA). To determine the adsorption model of interactions between anti-CCP solutions and anti-CCP/PAAm SPR sensor, different adsorption models were performed. The calculated maximum reflection, detection limit, association and dissociation constants were 1.079RU/mL, 0.177RU/mL, 0.589RU/mL and 1.697mL/RU, respectively. Repeatability experiments of anti-CCP/PAAm SPR sensor was performed four times with adsorption-desorption-regeneration cycles without any performance losing. Results showed that anti-CCP/PAAm SPR sensor had high selectivity and sensitivity for detection of CCP antibodies.