Development of a Molecular-Imprinted-Polymer based sensor for the electrochemical determination of Triacetone Triperoxide (TATP)

.The explosive triacetone triperoxide (TATP), which can be prepared from commercially readily available reagents following an easy synthetic procedure, is one of the most common components of improvised explosive devices (IEDs). Molecularly-imprinted polymer (MIP) electrochemical sensors have proved useful for the determination of different compounds in different matrices with the required sensitivity and selectivity. In this work, a highly sensitive and selective molecularly imprinted polymer with electrochemical capabilities for the determination of TATP has been developed. The molecular imprinting has been performed via electropolymerisation onto a glassy carbon electrode surface by cyclic voltammetry from a solution of pyrrole functional monomer, TATP template and LiClO4. Differential Pulse Voltammetry of TATP, with LiClO4 as supporting electrolyte, was performed in a potential range of −2.0 V to +1.0 V (vs. Ag/AgCl). Three-factor two-level factorial design was used to optimise the monomer concentration at 0.1 mol·L−1 , template concentration at 100 mmol·L−1 and the number of cyclic voltammetry scan cycles to 10. The molecularly imprinted polymer-modified glassy carbon electrode demonstrated good performance at low concentrations for a linear range of 82–44,300 µg·L−1 and a correlation coefficient of r2 = 0.996. The limits of detection (LoD) and quantification (LoQ) achieved were 26.9 μg·L−1 and 81.6 μg·L−1, respectively. The sensor demonstrated very good repeatability with precision values (n = 6, expressed as %RSD) of 1.098% and 0.55% for 1108 and 2216 µg·L−1 , respectively. It also proved selective for TATP in the presence of other explosive substances such as PETN, RDX, HMX, and TNT

Recent developments in sensing devices based on polymeric systems

This review is focused on the analysis of recent developments in the application of polymers in the detection and quantification of target species. The work begins with a description of the polymers that are employed as sensory materials, covering molecularly imprinted polymers or MIPs, hybrid polymers, acrylic polymers, conductive polymers, polymers with chiral motifs and also the use of polymeric arrays. After the description of the sensory polymers, the different target species which can be detected using sensory polymeric devices, including metallic cations and anionic species, gases, explosives, radionuclides and bacteria or the recent biomedical and biological applications is described. Finally, the sensory devices fabricated using smart polymers, including, for example, sensory devices based on Quartz Crystal Microbalances or the use of micro and nanoporous materials as substrates for sensory polymeric coatings is listed and reviewed. The work also details the different detection mechanisms based on the type of response of the sensory polymers, such as electrical, piezoelectric or fluorescence. In brief, the review details a review of the research work published in the last 10 years in this quickly evolving field, with special emphasis in the biomedical and biological applications, which have emerged recently raising great attention. To conclude, some perspectives and future challenges that must be overcome by this research field in the next years is exposed.FEDER (Fondo Europeo de Desarrollo Regional) and the Spanish Agencia Estatal de Investigación (AEI) (MAT2017-84501-R

Smart polymers in micro and nano sensory devices

The present review presents the most recent developments concerning the application of sensory polymers in the detection and quantification of different target species. We will firstly describe the main polymers that are being employed as sensory polymers, including, for example, conducting or acrylate-based polymers. In the second part of the review, we will briefly describe the different mechanisms of detection and the target species, such as metal cations and anions, explosives, and biological and biomedical substances. To conclude, we will describe the advancements in recent years concerning the fabrication of micro and nano sensory devices based on smart polymers, with a bibliographic revision of the research work published between 2005 and today, with special emphasis on research work presented since 2010. A final section exposing the perspectives and challenges of this interesting research line will end the present review article.FEDER (Fondo Europeo de DEsarrollo Regional), and both the Spanish Ministerio de Economía, Industria y Competitividad (MAT2014-54137-R, MAT2017-84501-R) and the Consejería de Educación–Junta de Castilla y León (BU061U16

Molecularly imprinted polymer-based sensors for priority pollutants

Globally, there is growing concern about the health risks of water and air pollution. The U.S. Environmental Protection Agency (EPA) has developed a list of priority pollutants containing 129 different chemical compounds. All of these chemicals are of significant interest due to their serious health and safety issues. Permanent exposure to some concentrations of these chemicals can cause severe and irrecoverable health effects, which can be easily prevented by their early identification. Molecularly imprinted polymers (MIPs) offer great potential for selective adsorption of chemicals from water and air samples. These selective artificial bio(mimetic) receptors are promising candidates for modification of sensors, especially disposable sensors, due to their low-cost, long-term stability, ease of engineering, simplicity of production and their applicability for a wide range of targets. Herein, innovative strategies used to develop MIP-based sensors for EPA priority pollutants will be reviewed. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Nanomaterials for Healthcare Biosensing Applications

In recent years, an increasing number of nanomaterials have been explored for their applications in biomedical diagnostics, making their applications in healthcare biosensing a rapidly evolving field. Nanomaterials introduce versatility to the sensing platforms and may even allow mobility between different detection mechanisms. The prospect of a combination of different nanomaterials allows an exploitation of their synergistic additive and novel properties for sensor development. This paper covers more than 290 research works since 2015, elaborating the diverse roles played by various nanomaterials in the biosensing field. Hence, we provide a comprehensive review of the healthcare sensing applications of nanomaterials, covering carbon allotrope-based, inorganic, and organic nanomaterials. These sensing systems are able to detect a wide variety of clinically relevant molecules, like nucleic acids, viruses, bacteria, cancer antigens, pharmaceuticals and narcotic drugs, toxins, contaminants, as well as entire cells in various sensing media, ranging from buffers to more complex environments such as urine, blood or sputum. Thus, the latest advancements reviewed in this paper hold tremendous potential for the application of nanomaterials in the early screening of diseases and point-of-care testing

EXPLORING SPECIFICITY AND STABILITY OF A MOLECULARLY IMPRINTED POLYMER

Molecularly imprinted polymers (MIPs) have numerous practical applications, including integration with quartz crystal microbalances to make specific, stable, chemical sensors, but most published research literature does not provide details concerning the specificity or stability of such an imprinted polymer. A polymer made from polyacrylic acid monomers, templated with benzoic acid, was tested for specificity with solutions of benzoic acid, acetic acid, phenol, and terephthalic acid passed through samples of uniform size under vacuum filtration. Additionally, MIP samples were also stored for extended periods of time in varied microclimates and then tested for performance, and consequently, stability. Initial conclusions indicate that a benzoic acid-templated MIP can capture the specific targets of benzoic acid, benzaldehyde, and terephthalic acid, while excluding species of similar size and functionality. Furthermore, benzoic acid-templated MIPs operate best when stored in a dry environment between 9ºC and far below 120ºC with shelf-lives for at least months

Bulk and Surface Acoustic Wave Sensor Arrays for Multi-Analyte Detection: A Review

Bulk acoustic wave (BAW) and surface acoustic wave (SAW) sensor devices have successfully been used in a wide variety of gas sensing, liquid sensing, and biosensing applications. Devices include BAW sensors using thickness shear modes and SAW sensors using Rayleigh waves or horizontally polarized shear waves (HPSWs). Analyte specificity and selectivity of the sensors are determined by the sensor coatings. If a group of analytes is to be detected or if only selective coatings (i.e., coatings responding to more than one analyte) are available, the use of multi-sensor arrays is advantageous, as the evaluation of the resulting signal patterns allows qualitative and quantitative characterization of the sample. Virtual sensor arrays utilize only one sensor but combine itwith enhanced signal evaluation methods or preceding sample separation, which results in similar results as obtained with multi-sensor arrays. Both array types have shown to be promising with regard to system integration and low costs. This review discusses principles and design considerations for acoustic multi-sensor and virtual sensor arrays and outlines the use of these arrays in multi-analyte detection applications, focusing mainly on developments of the past decade

Synthesis And Characterization Of Molecularly Imprinted Cross-Linked Poly (4-Vinylpyridine) For The Recognition And Concentrationdetermination Of Bilirubin In Solution

In this work molecularly imprinted polymer (MIP) film for the recognition of bilirubin was synthesized and studied using the Quartz Crystal Microbalance (QCM). The MIP was coated on the QCM crystals and analyzed using QCM. 4-vinylpyridine was used as functional monomer, divinylbenzene as cross-linking agent and benzophenone as initiator

A Novel Mobile Device for Environmental Hydrocarbon Sensing and Its Applications

abstract: The accurate and fast determination of organic air pollutants for many applications and studies is critical. Exposure to volatile organic compounds (VOCs) has become an important public health concern, which may induce a lot of health effects such as respiratory irritation, headaches and dizziness. In order to monitor the personal VOCs exposure level at point-of-care, a wearable real time monitor for VOCs detection is necessary. For it to be useful in real world application, it requires low cost, small size and weight, low power consumption, high sensitivity and selectivity. To meet these requirements, a novel mobile device for personal VOCs exposure monitor has been developed. The key sensing element is a disposable molecularly imprinted polymer based quartz tuning fork resonator. The sensor and fabrication protocol are low cost, reproducible and stable. Characterization on the sensing material and device has been done. Comparisons with gold standards in the field such as GC-MS have been conducted. And the device’s functionality and capability have been validated in field tests, proving that it’s a great tool for VOCs monitoring under different scenarios.Dissertation/ThesisDoctoral Dissertation Chemical Engineering 201

Current Trends in Molecular Imprinting: Strategies, Applications and Determination of Target Molecules in Spain

Over the last decades, an increasing demand for new specific molecular recognition elements has emerged in order to improve analytical methods that have already been developed in order to reach the detection/quantification limits of target molecules. Molecularly imprinted polymers (MIPs) have molecular recognition abilities provided by the presence of a template molecule during their synthesis, and they are excellent materials with high selectivity for sample preparation. These synthetic polymers are relatively easy to prepare, and they can also be an excellent choice in the substitution of antibodies or enzymes in different kinds of assays. They have been properly applied to the development of chromatographic or solid-phase extraction methods and have also been successfully applied as electrochemical, piezoelectrical, and optical sensors, as well as in the catalysis process. Nevertheless, new formats of polymerization can also provide new applications for these materials. This paper provides a comprehensive comparison of the new challenges in molecular imprinting as materials of the future in Spai