Selective PQQPFPQQ Gluten Epitope Chemical Sensor with a Molecularly Imprinted Polymer Recognition Unit and an Extended-Gate Field-Effect Transistor Transduction Unit.

A molecularly imprinted polymer (MIP) recognition system was devised for selective determination of an immunogenic gluten octamer epitope, PQQPFPQQ. For that, a thin MIP film was devised, guided by density functional theory calculations, and then synthesized to become the chemosensor recognition unit. Bis(bithiophene)-based cross-linking and functional monomers were used for this synthesis. An extended-gate field-effect transistor (EG-FET) was used as the transduction unit. The EG-FET gate surface was coated with the PQQPFPQQ-templated MIP film, by electropolymerization, to result in a complete chemosensor. X-ray photoelectron spectroscopy analysis confirmed the presence of the PQQPFPQQ epitope, and its removal from the MIP film. The chemosensor selectively discriminated between the octamer analyte and another peptide of the same number of amino acids but with two of them mismatched (PQQQFPPQ). The chemosensor was validated with respect to both the PQQPFPQQ analyte and a real gluten extract from semolina flour. It was capable to determine PQQPFPQQ in the concentration range of 0.5-45 ppm with the limit of detection (LOD) = 0.11 ppm. Moreover, it was capable of determining gluten in real samples in the concentration range of 4-25 ppm with LOD = 4 ppm, which is a value sufficient for discriminating between gluten-free and non-gluten-free food products. The gluten content in semolina flour determined with the chemosensor well correlated with that determined with a commercial ELISA gluten kit. The Langmuir, Freundlich, and Langmuir-Freundlich isotherms were fitted to the epitope sorption data. The sorption parameters determined from these isotherms indicated that the imprinted cavities were quite homogeneous and that the epitope analyte was chemisorbed in them

Idiopathic pulmonary fibrosis (IPF): Diagnostic routes using novel biomarkers

Idiopathic pulmonary fibrosis (IPF) diagnosis is still the diagnosis of exclusion. Differentiating from other forms of interstitial lung diseases (ILDs) is essential, given the various therapeutic approaches. The IPF course is now unpredictable for individual patients, although some genetic factors and several biomarkers have already been associated with various IPF prognoses. Since its early stages, IPF may be asymptomatic, leading to a delayed diagnosis. The present review critically examines the recent literature on molecular biomarkers potentially useful in IPF diagnostics. The examined biomarkers are grouped into breath and sputum biomarkers, serologically assessed extracellular matrix neoepitope markers, and oxidative stress biomarkers in lung tissue. Fibroblasts and complete blood count have also gained recent interest in that respect. Although several biomarker candidates have been profiled, there has yet to be a single biomarker that proved specific to the IPF disease. Nevertheless, various IPF biomarkers have been used in preclinical and clinical trials to verify their predictive and monitoring potential

Extended-gate field-effect transistor (EG-FET) with molecularly imprinted polymer (MIP) film for selective inosine determination

A novelrecognitionunitofchemicalsensorforselectivedeterminationoftheinosine,renaldisfunction biomarker,wasdevisedandprepared.Forthatpurpose,inosine-templatedmolecularlyimprinted polymer (MIP) film wasdepositedonanextended-gate field-effect transistor(EG-FET)signaltransducing unit. TheMIP film waspreparedbyelectrochemicalpolymerizationofbis(bithiophene)derivatives bearing cytosineandboronicacidsubstituents,inthepresenceoftheinosinetemplateandathiophene cross-linker.AfterMIP film deposition,thetemplatewasremoved,andwasconfirmed byUV\u2013visible spectroscopy.Subsequently,the film compositionwascharacterizedbyspectroscopictechniques,andits morphology andthicknessweredeterminedbyAFM.The finally MIP film-coated extended-gate fieldeffect transistor(EG-FET)wasusedforsignaltransduction.Thiscombinationisnotwidelystudiedinthe literature,despitethefactthatitallowsforfacileintegrationofelectrodepositedMIP film withFET transducer. The lineardynamicconcentrationrangeofthechemosensorwas0.5\u201350 \u3bcM withinosinedetect- ability of0.62 \u3bcM. Theobtaineddetectabilitycompareswelltothelevelsoftheinosineinbody fluids which areintherange0\u20132.9 mM forpatientswithdiagnoseddiabeticnephropathy,goutorhyperur- icemia, andcanreach25 mM incertaincases.Theimprintingfactorforinosine,determinedfrompie- zomicrogravimetricexperimentswithuseoftheMIP film-coated quartzcrystalresonator,wasfoundto be 5.5.Higherselectivityforinosinewithrespecttocommoninterferentswasalsoachievedwiththe present molecularlyengineeredsensingelement.Theobtainedanalyticalparametersofthedevised chemosensor allowforitsuseforpracticalsamplemeasurements

Molecularly Imprinted Polymer Based Sensors For Medical Applications

Sensors have been extensively used owing to multiple advantages, including exceptional sensing performance, user-friendly operation, fast response, high sensitivity and specificity, portability, and real-time analysis. In recent years, efforts in sensor realm have expanded promptly, and it has already presented a broad range of applications in the fields of medical, pharmaceutical and environmental applications, food safety, and homeland security. In particular, molecularly imprinted polymer based sensors have created a fascinating horizon for surface modification techniques by forming specific recognition cavities for template molecules in the polymeric matrix. This method ensures a broad range of versatility to imprint a variety of biomolecules with different size, three dimensional structure, physical and chemical features. In contrast to complex and time-consuming laboratory surface modification methods, molecular imprinting offers a rapid, sensitive, inexpensive, easy-to-use, and highly selective approaches for sensing, and especially for the applications of diagnosis, screening, and theranostics. Due to its physical and chemical robustness, high stability, low-cost, and reusability features, molecularly imprinted polymer based sensors have become very attractive modalities for such applications with a sensitivity of minute structural changes in the structure of biomolecules. This review aims at discussing the principle of molecular imprinting method, the integration of molecularly imprinted polymers with sensing tools, the recent advances and strategies in molecular imprinting methodologies, their applications in medical, and future outlook on this concept.PubMedWoSScopu

Protein Determination with Molecularly Imprinted Polymer Recognition Combined with Birefringence Liquid Crystal Detection

Liquid crystal-based sensors offer the advantage of high sensitivity at a low cost. However, they often lack selectivity altogether or require costly and unstable biomaterials to impart this selectivity. To incur this selectivity, we herein integrated a molecularly imprinted polymer (MIP) film recognition unit with a liquid crystal (LC) in an optical cell transducer. We tested the resulting chemosensor for protein determination. We examined two different LCs, each with a different optical birefringence. That way, we revealed the influence of that parameter on the sensitivity of the (human serum albumin)-templated (MIP-HSA) LC chemosensor. The response of this chemosensor with the (MIP-HSA)-recognizing film was linear from 2.2 to 15.2 µM HSA, with a limit of detection of 2.2 µM. These values are sufficient to use the devised chemosensor for HSA determination in biological samples. Importantly, the imprinting factor (IF) of this chemosensor was appreciable, reaching IF = 3.7. This IF value indicated the predominant binding of the HSA through specific rather than nonspecific interactions with the MIP

Molecularly imprinted polymer based extended-gate field-effect transistor chemosensors for phenylalanine enantioselective sensing

This article discusses the design and synthesis of molecularly imprinted polymers, guided by DFT calculations