In the global market era, food product control is very challenging. It is impossible to track and control all production and delivery chains not only for regular customers but also for the State ...Sanitary Inspections. Certified laboratories currently use accurate food safety and quality inspection methods. However, these methods are very laborious and costly. The present review highlights the need to develop fast, robust, and cost-effective analytical assays to determine food contamination. Application of the molecularly imprinted polymers (MIPs) as selective recognition units for chemosensors' fabrication was herein explored. MIPs enable fast and inexpensive electrochemical and optical transduction, significantly improving detectability, sensitivity, and selectivity. MIPs compromise durability of synthetic materials with a high affinity to target analytes and selectivity of molecular recognition. Imprinted molecular cavities, present in MIPs structure, are complementary to the target analyte molecules in terms of size, shape, and location of recognizing sites. They perfectly mimic natural molecular recognition. The present review article critically covers MIPs' applications in selective assays for a wide range of food products. Moreover, numerous potential applications of MIPs in the food industry, including sample pretreatment before analysis, removal of contaminants, or extraction of high-value ingredients, are discussed.
Molecular recognition, i.e., ability of one molecule to recognize another through weak bonding interactions, is one of the bases of life. It is often implemented to sensing systems of high merits. ...Preferential recognition of the analyte (guest) by the receptor (host) induces changes in physicochemical properties of the sensing system. These changes are measured by using suitable signal transducers. Because of possibility of miniaturization, fast response, and high sensitivity, field-effect transistors (FETs) are more frequently being used for that purpose. A FET combined with a biological material offers the potential to overcome many challenges approached in sensing. However, low stability of biological materials under measurement conditions is a serious problem. To circumvent this problem, synthetic receptors were integrated with the gate surface of FETs to provide robust performance. In the present critical review, the approach utilized to devise chemosensors integrating synthetic receptors and FET transduction is discussed in detail. The progress in this field was summarized and important outcome was provided.
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•The approaches utilized to integrate synthetic receptors and FETs are reviewed.•Synthetic receptors can provide the desired selectivity to FETs.•The EG-FETs integrated with synthetic recognition films have wider applications.•Importance of minimizing or overcoming ionic screening effects is stressed.
► Achievements in fabrication of MIP sensors for biohazards are critically evaluated. ► Analytical parameters of the MIP sensors are compiled. ► Solutions of the problems encountered in sensing are ...highlighted. ► New trends in MIP sensing of biohazards and drug of abuse are highlighted.
Environmental and health safety requires thorough determination of hazardous compounds and drugs of abuse. In determinations of these analytes, traditional instrumental analytical techniques often suffer from tedious assay procedures.
Biosensors are simpler to construct and faster in use, so they can better meet the analytical demands in determination of these biohazards. However, their stability and reproducibility when operating under harsh conditions are poor, so artificial recognition units have become attractive as replacements for natural receptors in sensing applications.
Molecular imprinting is one of the most powerful tools for preparing materials that can bind analytes reversibly and selectively in the presence of their interferents.
This review critically evaluates the development of chemical sensing of biohazards and drugs of abuse using the molecular-imprinting approach to recognition in combination with different ways of analytical signal transduction.
We compile analytical parameters of the molecularly-imprinted receptors, identify difficulties in the determinations encountered and highlight proposed solutions to problems.
Glyphosate (GLP) and GLP-based herbicides (GBHs), such as polyethoxylated tallow amine-based GLP surfactants (GLP-SH), developed in the late 70′, have become the most popular and controversial ...agrochemicals ever produced. Nowadays, GBHs have reached 350 million hectares of crops in over 140 countries, with an annual turnover of 5 billion and 11 billion USD in the U.S.A. and worldwide, respectively. Because of the highly efficient inhibitory activity of GLP targeted to the 5-enolpyruvylshikimate-3-phosphate synthase pathway, present in plants and several bacterial strains, the GLP-resistant crop-based genetic agricultural revolution has decreased famine and improved the costs and quality of living in developing countries. However, this progress has come at the cost of the 50-year GBH overuse, leading to environmental pollution, animal intoxication, bacterial resistance, and sustained occupational exposure of the herbicide farm and companies’ workers. According to preclinical and clinical studies covered in the present review, poisoning with GLP, GLP-SH, and GBHs devastatingly affects gut microbiota and the microbiota-gut-brain (MGB) axis, leading to dysbiosis and gastrointestinal (GI) ailments, as well as immunosuppression and inappropriate immunostimulation, cholinergic neurotransmission dysregulation, neuroendocrinal system disarray, and neurodevelopmental and neurobehavioral alterations. Herein, we mainly focus on the contribution of gut microbiota (GM) to neurological impairments, e.g., stroke and neurodegenerative and neuropsychiatric disorders. The current review provides a comprehensive introduction to GLP’s microbiological and neurochemical activities, including deviation of the intestinal Firmicutes-to-Bacteroidetes ratio, acetylcholinesterase inhibition, excitotoxicity, and mind-altering processes. Besides, it summarizes and critically discusses recent preclinical studies and clinical case reports concerning the harmful impacts of GBHs on the GI tract, MGB axis, and nervous system. Finally, an insightful comparison of toxic effects caused by GLP, GBH-SH, and GBHs is presented. To this end, we propose a first-to-date survey of clinical case reports on intoxications with these herbicides.
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•Misapplication of glyphosate-based herbicides has led to environmental pollution.•Dysbiotic, immunotoxic glyphosate alters microbiota-gut-brain axis functionality.•Glyphosate dysregulates hypothalamic-pituitary-adrenal neuroimmunomodulation.•Glyphosate deviates neurotransmission and cognitive and neurobehavioral abilities.•Occupational exposure to glyphosate links to paralytic ileus and parkinsonism.
Nanostructured artificial receptor materials with unprecedented hierarchical structure for determination of human serum albumin (HSA) are designed and fabricated. For that purpose a new hierarchical ...template is prepared. This template allowed for simultaneous structural control of the deposited molecularly imprinted polymer (MIP) film on three length scales. A colloidal crystal templating with optimized electrochemical polymerization of 2,3′-bithiophene enables deposition of an MIP film in the form of an inverse opal. Thickness of the deposited polymer film is precisely controlled with the number of current oscillations during potentiostatic deposition of the imprinted poly(2,3′-bithiophene) film. Prior immobilization of HSA on the colloidal crystal allows formation of molecularly imprinted cavities exclusively on the internal surface of the pores. Furthermore, all binding sites are located on the surface of the imprinted cavities at locations corresponding to positions of functional groups present on the surface of HSA molecules due to prior derivatization of HSA molecules with appropriate functional monomers. This synergistic strategy results in a material with superior recognition performance. Integration of the MIP film as a recognition unit with a sensitive extended-gate field-effect transistor (EG-FET) transducer leads to highly selective HSA determination in the femtomolar concentration range.
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•A hierarchical template for electrosynthesis of a nanostructured MIP was prepared.•Structure of deposited MIP film was simultaneously controlled on three size scales.•A colloidal crystal templating enables deposition of an inverse opal MIP film.•Thickness of deposited MIP film is precisely controlled by current oscillations.•An MIP-EG-FET transducer allowed for HSA determination in fM concentration range.
An insulin-imprinted polymer was synthesized over the surface of vinyl group functionalized multiwalled carbon nanotubes, using phosphotidylcholine-containing functional monomer and cross-linker. ...Phosphotidylcholine is a major component of all biological membrane; its incorporation in polymer backbone assures water-compatibility, bio-compatibility and specificity to molecularly imprinted nanomaterials, without any cross-reactivity or interferences from biological sample matrices. An electrochemical sensor fabricated by modifying multiwalled carbon nanotubes-molecularly imprinted polymer onto the pencil graphite electrode, was used for trace level detection of insulin in aqueous, blood serum, and pharmaceutical samples (detection limit 0.0186
nmol
L
−1, S/N
=
3), by differential pulse anodic stripping voltammetry. Additional cyclic voltammetry (stripping mode) and chronocoulometry experiments were performed to explore electrodics and kinetics of electro-oxidation of insulin.
The present review has sought to explore the technological advances that have been made in recent years towards the selective analysis of uric acid and critically evaluate how they could, in fact, be ...exploited as a basis for a multi analyte sensor incorporating uric acid detection. Numerous strategies have evolved in recent years but these have invariably focused on the manufacture and response characterization of discrete sensors. Various methods of obtaining selective detection such as use of uricase enzymes, nanoparticles, carbon nanotubes, polymers, conducting polymers and MIPs are also discussed along with the clinical relevance of UA determination.
Herein we described a post-imprinting modification of the imprinted molecular cavities for electrochemical sensing of a target protein. Imprinted molecular cavities were generated by following the ...semi-covalent surface imprinting approach. These mesoporous cavities were modified with a ferrocene 'electrochemical' tracer for electrochemical transduction of the target protein recognition. Electrochemical sensors prepared after post-imprinting modification showed a linear response in the concentration range of 0.5 to 50 μM. Chemosensors fabricated based on capacitive impedimetric transduction demonstrated that imprinted molecular cavities without post-imprinting modification showed better selectivity. Scanning electrochemical microscopy (SECM) was used for the surface characterization of imprinted molecular cavities modified with ferrocene electrochemical tracers. SECM analysis performed in the feedback mode monitor changes in the surface state of the ferrocene-modified polymer film. The kinetics of the mediator regeneration was almost 1.8 times higher on the non-imprinted surface
versus
the post-imprinting modified molecular imprinted polymer.
Post-imprinting modification of imprinted molecular cavities with a 'redox probe for electrochemical sensing.
A molecularly imprinted polymer (MIP)‐based chemosensor for the selective determination of a chosen toxin, N‐nitroso‐l‐proline (Pro‐NO), was devised and fabricated. By means of DFT, the structure of ...the pre‐polymerization (functional monomer)–template complex was modeled. This complex was then potentiodynamically electropolymerized in the presence of cross‐linking monomer to form a MIP–Pro‐NO thin film. Next, the Pro‐NO template was extracted from MIP–Pro‐NO with 0.1 m NaOH. Piezoelectric microgravimetry (PM) on an electrochemical quartz crystal microbalance and electrochemical (differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS)) techniques were used to transduce binding of Pro‐NO to molecular cavities of the MIP–Pro‐NO. With DPV and EIS chemosensing, the limits of detection (LODs) were about 80.9 and 36.9 nM Pro‐NO, respectively; and the selectivity coefficients for urea, glucose, creatinine, and adrenalin interferences were 6.6, 13.2, 2.1, and 2.0, respectively, with DPV as well as 2.3, 2.0, 3.3, and 2.5, respectively, with EIS. With PM under flow injection analysis conditions, the LOD was 10 μm Pro‐NO. The MIP–Pro‐NO chemosensor detectability and selectivity with respect to interferences were sufficiently high to determine Pro‐NO in protein‐providing food products.
Plastic antibodies for food safety: A molecularly imprinted polymer (MIP, “plastic antibody”)‐based chemosensor for the selective determination of a chosen food toxin, N‐nitroso‐l‐proline (Pro‐NO), was devised and fabricated (see figure). The MIP–Pro‐NO chemosensor detectability and selectivity with respect to interferences were sufficiently high to determine Pro‐NO in protein‐providing food products.
A simple polymerization strategy is reported in this work which allows molecularly imprinted polymeric fiber (monolith) fabrication for direct use in sensing devices. This is advantageous for ...achieving higher degree of enrichment of target analyte (folic acid) from the complex matrices of real samples, without any surface fouling, cross-reactivity, and non-specific (false-positive) contributions. In order to measure serum folic acid at ultratrace level to detect spina bifida, a neural tube defect in mother, and other acute cases of proteomic diseases, the hyphenation between molecularly imprinted micro-solid phase extraction fiber and a complementary molecularly imprinted polymer–carbon composite fiber sensor has been found quite efficient. The primitive diagnosis of many chronic diseases is feasible by estimating folic acid as biomarker, with the detection limit as low as 0.0036
ng
mL
−1 (relative standard deviation
=
0.13%, signal/noise
=
3) in human blood serum.
