Rüstem Keçili

Valorisation of agricultural waste with an adsorption/nanofiltration hybrid process: from materials to sustainable process design

Downstream processing is considered to be the bottleneck in pharmaceutical manufacturing because its development has not kept pace with upstream production. In some cases, the lack of efficient downstream processing capacity can seriously affect both the sustainability and profitability of a pharmaceutical product and even result in its failure. Minimising solvent and raw material consumption, as well as utilising waste, can make a significant difference towards environmentally benign and economically viable chemical production. In this work, the authors present the development and modelling of a continuous adsorption process with in situ solvent recovery for the isolation of oleuropein from olive leaves, an agricultural waste. Waste utilisation in agriculture has gained increasing attention because this economic sector is ranked as the 2nd highest global greenhouse gas emission contributor. Imprinted polymers were developed for the selective scavenging of oleuropein from olive leaf extracts using green solvents. The mild temperature-swing (25–43 °C) process allows the continuous isolation of oleuropein at 1.75 g product per kg of adsorbent per hour with an unprecedented 99.7% purity. In situ solvent recovery was realized with a solvent-resistant nanofiltration membrane allowing 97.5% solvent recycle and 44.5% total carbon footprint reduction, while concentrating both the product stream for crystallisation and the waste stream for disposal.

Fast identification of selective resins for removal of genotoxic aminopyridine impurities via screening of molecularly imprinted polymer libraries

This study describes the identification and evaluation of molecularly imprinted polymers (MIPs) for the selective removal of potentially genotoxic aminopyridine impurities from pharmaceuticals. Screening experiments were performed using existing MIP resin libraries to identify resins selective towards those impurities in the presence of model pharmaceutical compounds. A hit resin with a considerable imprinting effect was found in the screening and upon further investigation, the resin was found to show a broad selectivity towards five different aminopyridines in the presence of the two model active pharmaceutical ingredients (APIs) piroxicam and tenoxicam.

4-Aminophenyl boronic acid modified gold platforms for influenza diagnosis

As a potential pandemic threat to human health, there has been an urgent need for rapid, sensitive, simpler and less expensive detection method for the highly pathogenic influenza A virus. For this purpose, Quartz Crystal Microbalance (QCM) and Surface Plasmon Resonance (SPR) sensors have been developed for the recognition of hemagglutinin (HA) which is a major protein of influenza A virus. 4-Aminophenyl boronic acid (4-APBA) has been synthesized and used as a new ligand for binding of sialic acid (SA) via boronic acid-sugar interaction. SA has an important role in binding of HA. QCM and SPR sensor surfaces have been modified with thiol groups and then 4-APBA and SA have been immobilized on sensor surfaces, respectively. Sensor surfaces have been screened with AFM and used for the determination of HA from aqueous solution. The selective recognition of the QCM and SPR sensors toward Concanavalin A has been reported in this work. Also, the binding capacity and detection limits of QCM and SPR sensors have been calculated and detection limits were found to be 4.7 × 10(-2) μM, (0.26 μg ml(-1)) and 1.28 × 10(-1) μM, (0.72 μg ml(-1)) in the 95% confidence interval, respectively.

Molecular Imprinting Technology in Quartz Crystal Microbalance (QCM) Sensors.

Molecularly imprinted polymers (MIPs) as artificial antibodies have received considerable scientific attention in the past years in the field of (bio)sensors since they have unique features that distinguish them from natural antibodies such as robustness, multiple binding sites, low cost, facile preparation and high stability under extreme operation conditions (higher pH and temperature values, etc.). On the other hand, the Quartz Crystal Microbalance (QCM) is an analytical tool based on the measurement of small mass changes on the sensor surface. QCM sensors are practical and convenient monitoring tools because of their specificity, sensitivity, high accuracy, stability and reproducibility. QCM devices are highly suitable for converting the recognition process achieved using MIP-based memories into a sensor signal. Therefore, the combination of a QCM and MIPs as synthetic receptors enhances the sensitivity through MIP process-based multiplexed binding sites using size, 3D-shape and chemical function having molecular memories of the prepared sensor system toward the target compound to be detected. This review aims to highlight and summarize the recent progress and studies in the field of (bio)sensor systems based on QCMs combined with molecular imprinting technology.

Design and Preparation of Nano-Lignin Peroxidase (NanoLiP) by Protein Block Copolymerization Approach

This study describes the preparation of nanoprotein particles having lignin peroxidase (LiP) using a photosensitive microemulsion polymerization technique. The protein-based nano block polymer was synthesized by cross-linking of ligninase enzyme with ruthenium-based aminoacid monomers. This type polymerization process brought stability in different reaction conditions, reusability and functionality to the protein-based nano block polymer system when compared the traditional methods. After characterization of the prepared LiP copolymer nanoparticles, enzymatic activity studies of the nanoenzymes were carried out using tetramethylbenzidine (TMB) as the substrate. The parameters such as pH, temperature and initial enzyme concentration that affect the activity, were investigated by using prepared nanoLip particles and compared to free LiP. The reusability of the nano-LiP particles was also investigated and the obtained results showed that the nano-LiP particles exhibited admirable potential as a reusable catalyst.

Mechanism of Adsorption on Nanomaterials

Abstract Nanomaterials have unique chemical and physical features such as a large surface area, small size, and high stability compared to conventional bulk materials. Therefore, they are widely used for the adsorption of different compounds in environmental, biological, and food samples. On the other hand, it is crucial to investigate the adsorption mechanisms, kinetics, and the thermodynamics to understand the nature of the adsorption process. Thus several isotherm and kinetic models are applied to the adsorption systems to achieve this goal. This chapter highlights the recent applications of the nanoadsorbents in the literature. The adsorption mechanisms, kinetics, and thermodynamics of the reported examples are also described.

Concanavalin A photocross-linked affinity cryogels for the purification of horseradish peroxidase:

The present study describes an easy and efficient procedure for the purification of horseradish peroxidase from horseradish roots. For this purpose, supermacroporous cryogels having Concanavalin A were prepared by photosensitive cross-linking polymerization. Horseradish peroxidase binding and elution from the prepared cryogels were carried out changing various parameters such as initial peroxidase concentration and pH. The best binding performance was obtained at pH 7.0. The maximum horseradish peroxidase binding of the cryogels was found to be 3.85 mg g−1 cryogel. Horseradish peroxidase purification from crude extract resulted in 115.1-fold. SDS-PAGE analysis and circular dichroism measurements indicated that the horseradish peroxidase purification from horseradish roots was successfully carried out.

Engineered Nanosensors Based on Molecular Imprinting Technology

Abstract Natural antibody-based biosensors have some disadvantages such as low stability and high production cost. Therefore, innovative engineered materials with higher selectivity and sensitivity are needed for the recognition of the desired compound. Molecularly imprinted polymers (MIPs), also called “plastic antibodies,” are a kind of materials having 3D cavities (shape of the target compound), binding groups, and exhibit high binding affinity and selectivity toward the desired compound. MIPs as plastic antibodies have gained great attention in biosensor applications in the past decades since they are stable, cheap, robust, and selective. This chapter aims to summarize and highlight the recent progresses in the field of nanobiosensor platforms based on molecular imprinting technique.

Selective Recognition of Myoglobin in Biological Samples Using Molecularly Imprinted Polymer-Based Affinity Traps

The current work demonstrates the design, characterization, and preparation of molecularly imprinted microspheres for the selective detection of myoglobin in serum samples. The suspension polymerization approach was applied for the preparation of myoglobin imprinted microspheres. For this purpose, N-methacryloylamino folic acid-Nd3+ (MAFol- Nd3+) was chosen as the complex functional monomer. The optimization studies were performed changing the medium pH, temperature, and myoglobin concentration. pH 7.0 was determined as the optimum value where the prepared imprinted microspheres displayed maximum binding for myoglobin. The maximum binding capacity was achieved as 623 mgg−1. In addition, the selectivity studies were conducted. The results confirmed that the imprinted microspheres showed great selectivity towards myoglobin in the existence of hemoglobin, cytochrome c, and lysozyme which were chosen as potentially competing proteins.

Recent Progress of Imprinted Nanomaterials in Analytical Chemistry

Molecularly imprinted polymers (MIPs) are a type of tailor-made materials that have ability to selectively recognize the target compound/s. MIPs have gained significant research interest in solid-phase extraction, catalysis, and sensor applications due to their unique properties such as low cost, robustness, and high selectivity. In addition, MIPs can be prepared as composite nanomaterials using nanoparticles, multiwalled carbon nanotubes (MWCNTs), nanorods, quantum dots (QDs), graphene, and clays. This review paper aims to demonstrate and highlight the recent progress of the applications of imprinted nanocomposite materials in analytical chemistry.