Determination of sitagliptin in human plasma using a smart electrochemical sensor based on electroactive molecularly imprinted nanoparticles

Electrochemical Assays for the Determination of Antidiabetic Drugs-A Review

This article presents the current state of knowledge regarding electrochemical methods for determining the active substances within drugs that are used in the treatment of type 1 and type 2 diabetes. Electrochemical methods of analysis, due to their sensitivity and easiness, are a great alternative to other, usually more expensive analytical assays. The determination of active substances mentioned in this review is based on oxidation or reduction processes on the surface of the working electrode. A wide variety of working electrodes, often modified with materials such as nanoparticles or conducting polymers, have been used for the highly sensitive analysis of antidiabetic drugs. The presented assays allow us to determine the compounds of interest in various samples, such as pharmaceutical products or different human bodily fluids.

Transitioning from Supramolecular Chemistry to Molecularly Imprinted Polymers in Chemical Sensing

This perspective article focuses on the overwhelming significance of molecular recognition in biological processes and its emulation in synthetic molecules and polymers for chemical sensing. The historical journey, from early investigations into enzyme catalysis and antibody-antigen interactions to Nobel Prize-winning breakthroughs in supramolecular chemistry, emphasizes the development of tailored molecular recognition materials. The discovery of supramolecular chemistry and molecular imprinting, as a versatile method for mimicking biological recognition, is discussed. The ability of supramolecular structures to develop selective host-guest interactions and the flexible design of molecularly imprinted polymers (MIPs) are highlighted, discussing their applications in chemical sensing. MIPs, mimicking the selectivity of natural receptors, offer advantages like rapid synthesis and cost-effectiveness. Finally, addressing major challenges in the field, this article summarizes the advancement of molecular recognition-based systems for chemical sensing and their transformative potential.

Imprinted Hydrogel Nanoparticles for Protein Biosensing: A Review

Over the past decade, molecular imprinting (MI) technology has made tremendous progress, and the advancements in nanotechnology have been the major driving force behind the improvement of MI technology. The preparation of nanoscale imprinted materials, i.e., molecularly imprinted polymer nanoparticles (MIP NPs, also commonly called nanoMIPs), opened new horizons in terms of practical applications, including in the field of sensors. Currently, hydrogels are very promising for applications in bioanalytical assays and sensors due to their high biocompatibility and possibility to tune chemical composition, size (microgels, nanogels, etc.), and format (nanostructures, MIP film, fibers, etc.) to prepare optimized analyte-responsive imprinted materials. This review aims to highlight the recent progress on the use of hydrogel MIP NPs for biosensing purposes over the past decade, mainly focusing on their incorporation on sensing devices for detection of a fundamental class of biomolecules, the peptides and proteins. The review begins by directing its focus on the ability of MIPs to replace biological antibodies in (bio)analytical assays and highlight their great potential to face the current demands of chemical sensing in several fields, such as disease diagnosis, food safety, environmental monitoring, among others. After that, we address the general advantages of nanosized MIPs over macro/micro-MIP materials, such as higher affinity toward target analytes and improved binding kinetics. Then, we provide a general overview on hydrogel properties and their great advantages for applications in the field of Sensors, followed by a brief description on current popular routes for synthesis of imprinted hydrogel nanospheres targeting large biomolecules, namely precipitation polymerization and solid-phase synthesis, along with fruitful combination with epitope imprinting as reliable approaches for developing optimized protein-imprinted materials. In the second part of the review, we have provided the state of the art on the application of MIP nanogels for screening macromolecules with sensors having different transduction modes (optical, electrochemical, thermal, etc.) and design formats for single use, reusable, continuous monitoring, and even multiple analyte detection in specialized laboratories or in situ using mobile technology. Finally, we explore aspects about the development of this technology and its applications and discuss areas of future growth.

Electroactive molecularly imprinted polymer nanoparticles for selective glyphosate determination

Redox-active molecularly imprinted polymer nanoparticles selective for glyphosate, MIP-Gly NPs, were devised, synthesized, and subsequently integrated onto platinum screen-printed electrodes (Pt-SPEs) to fabricate a chemosensor for selective determination of glyphosate (Gly) without the need for redox probe in the test solution. That was because, ferrocenylmethyl methacrylate was added to the polymerization mixtures during the NPs synthesis so that the resulting MIP-Gly NPs contained covalently immobilized ferrocenyl moieties as the reporting redox ingredient, conferring these NPs with electroactive properties. MIP-Gly NPs of four different compositions were evaluated. The herein described approach represents a simple and effective way to endow MIP NPs with electrochemical reporting capabilities with neither the need to functionalize them post-synthesis nor to use electrochemical mediators present in the tested solution during the analyte determinations. MIP-Gly NPs synthesized using allylamine and squaramide-based monomers appeared most selective to Gly. The Pt-SPEs modified with MIP-Gly NPs were characterized with differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Changes in the DPV peak originating from the oxidation of the ferrocenyl moieties in these MIP-Gly NPs served as the analytical signal. The DPV limit of detection and the linear dynamic concentration range for Gly were 3.7 pM and 25 pM-500 pM, respectively. Moreover, the selectivity of the fabricated chemosensors was sufficiently high to determine Gly successfully in spiked river water samples.

The simultaneous quantification of Sitagliptin and Irbesartan in rat plasma using the validated LC-MS/MS method is applied to a pharmacokinetic study

Irbesartan (IRB), an angiotensin II receptor AT1 blocker, is an antihypertensive agent commonly used with Sitagliptin (STG), a novel antidiabetic agent in diabetes. A finalised and validated LC-MS/MS method was used for the bioanalytical quantification of STG and IRB to be applicable to studies on the P.K drug-drug interactions between STG and IRB. Using a YMC triart C18 column (50 mm × 4.6 mm i.d., 3 µm), both the drugs and the Tolbutamide were separated using a gradient mode with a flow rate of 1 ml/min with run time of 5 min. For analyte detection, an LC-MS/MS system with multiple reaction monitoring (MRM) was used. The technique was validated across a concentration range of 5-1000 ng/ml, with the LLOQ for both analytes being 5 ng/ml. At all QC levels accuracies from spiked samples were > 83% for both drugs and internal standards. The accuracy for STG within-batch and between-batch was found within 98.4-107.2%, and for IRB was found within 92.4-102.5%. The precision for STG within batch and between batches was less than 12.3% CV, and for IRB was less than 10.2% CV at all concentration levels. The pharmacokinetic profiles of STG and IRB were successfully applied on simultaneous oral administration to rats. This method applies to pharmacokinetic multidrug interaction studies.

Electrochemical sensing of macromolecules based on molecularly imprinted polymers: challenges, successful strategies, and opportunities

Looking at the literature focused on molecularly imprinted polymers (MIPs) for protein, it soon becomes apparent that a remarkable increase in scientific interest and exploration of new applications has been recorded in the last several years, from 42 documents in 2011 to 128 just 10 years later, in 2021 (Scopus, December 2021). Such a rapid threefold increase in the number of works in this field is evidence that the imprinting of macromolecules no longer represents a distant dream of optimistic imprinters, as it was perceived until only a few years ago, but is rapidly becoming an ever more promising and reliable technology, due to the significant achievements in the field. The present critical review aims to summarize some of them, evidencing the aspects that have contributed to the success of the most widely used strategies in the field. At the same time, limitations and drawbacks of less frequently used approaches are critically discussed. Particular focus is given to the use of a MIP for protein in the assembly of electrochemical sensors. Sensor design indeed represents one of the most active application fields of imprinting technology, with electrochemical MIP sensors providing the broadest spectrum of protein analytes among the different sensor configurations.

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