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RSC Advances Sep 2020We report a novel bioluminescent aptasensor, which consists of 2'-F-RNA aptamer modules joined into a bi-specific aptamer construct. One aptamer module binds the...
We report a novel bioluminescent aptasensor, which consists of 2'-F-RNA aptamer modules joined into a bi-specific aptamer construct. One aptamer module binds the analyte, then after structural rearrangement the second module recruits non-covalently Ca-dependent photoprotein obelin from the solution, thus providing a bioluminescent signal. This concept allows using free protein as a reporter, which brings such advantages as no need for aptamer-protein conjugation, a possibility of thermal re-folding of aptamer component with no harm to a protein, and simpler detection protocol. We developed the new 2'-F-RNA aptamer for obelin, and proposed the strategy for engineering structure-switching bi-modular aptamer constructs which bind the analyte and the obelin in a sequential manner. With the use of hemoglobin as a model analyte, we showed the feasibility of utilizing the aptasensor in a fast and straightforward bioluminescent microplate assay. With a proper design of a secondary structure, this strategy of aptasensor engineering might be further extended to bi-specific aptamer-based bioluminescent sensors for other analytes of interest.
PubMed: 35516485
DOI: 10.1039/d0ra05117a -
Nanoscale Jul 2023Nanoscience shows promise for scientific advancement in many sectors, such as biology, energy, materials, environment, and manufacturing. Nanocomposites are mixtures of... (Review)
Review
Nanoscience shows promise for scientific advancement in many sectors, such as biology, energy, materials, environment, and manufacturing. Nanocomposites are mixtures of two or more materials, one of which is nanosized particles. The composites are expected to show combined features resulting in general enhancements in their physical and chemical properties. Metal-organic frameworks (MOFs) are coordination polymers that have attracted attention from researchers in recent years due to their porosity and controllable functionality. Another example of interesting nanomaterials is carbon nanotubes (CNTs) which are also known for their mechanical and thermal properties. Incorporation of both these materials into a nanocomposite has shown an enhancement in properties and conquered challenges in the defects of construction. This mini-review sheds light on the recent synthetic approaches and characterization of MOF-CNT nanocomposites in order to access porous selective nanocomposites that can improve analyte detection in environmental matrixes and biological systems. A summary of the chemical composition of nanocomposites, analytes in the target, and analytical techniques used is provided.
PubMed: 37378958
DOI: 10.1039/d3nr01074k -
Scandinavian Journal of Clinical and... Apr 2022The analytical stability of laboratory tests relies mostly on internal and external quality control procedures. Summarized patient data has in several studies been shown...
The analytical stability of laboratory tests relies mostly on internal and external quality control procedures. Summarized patient data has in several studies been shown to be a good supplement for monitoring analytical stability. In our present investigation, we evaluate a datamining method for retrospective evaluation and assessment of analyte stability in whole blood. Results from the laboratory information system were used as the basis for the datamining approach. Blood tests were requested by the general practitioners and drawing of the blood sample was either at the general practitioner's or at the hospital outpatient clinics. We were able to split data into groups based on sample collection place and time to analysis. The datamining approach was compared to experiments where samples were incubated at a single temperature as well as an experiment where the temperatures were changed during incubation. To demonstrate the method, we selected three laboratory tests considered representative: potassium, phosphate, and lactate dehydrogenase. The datamining approach showed results similar to the reference experiment. Furthermore, our results show that the analytes phosphate and potassium were not stable after short storage at a lower temperature.
Topics: Blood Specimen Collection; Humans; Phosphates; Potassium; Retrospective Studies; Specimen Handling; Temperature
PubMed: 35112638
DOI: 10.1080/00365513.2022.2031280 -
Annales de Biologie Clinique Aug 2018Salivary cortisol assay, described for the first time almost forty years ago, has not been expanding until the last decade. Its simplicity, non-invasiveness and the easy... (Review)
Review
Salivary cortisol assay, described for the first time almost forty years ago, has not been expanding until the last decade. Its simplicity, non-invasiveness and the easy repetition of sampling make it an analytical matrix of interest. Since the publication of the recommendations of the American endocrinology society in 2008, salivary cortisol is recognized as one of the three main tests to screen for Cushing's syndrome. In addition, salivary cortisone, the major metabolite of salivary cortisol, still represents a severe potential interferent but could also be a complementary analyte for indications where evaluation of cortisol secretion is sought. Moreover, in the current context of practices and methods harmonization, the problem of lack of standardization presents also for salivary cortisol. This review briefly develops the three main tests of Cushing's syndrome screening to explain the reasons for integrating the saliva test into this screening. Then we will develop the variables that can influence salivary cortisol from a pre-analytic, physiopathological and finally analytical point of view.
Topics: Addison Disease; Circadian Rhythm; Cushing Syndrome; Humans; Hydrocortisone; Pre-Analytical Phase; Saliva; Specimen Handling
PubMed: 29952304
DOI: 10.1684/abc.2018.1355 -
Journal of Analytical Toxicology Sep 2021Analytical performance of stable isotope-labeled internal standardization (SIL-IS) and threshold accurate calibration (TAC) methods of matrix normalization are compared...
Analytical performance of stable isotope-labeled internal standardization (SIL-IS) and threshold accurate calibration (TAC) methods of matrix normalization are compared for quantitation of 51 drugs and metabolites (analytes) in urine with analysis by ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS-MS). Two SIL-IS methods of analysis were performed, one method using analyte-specific internal standardization (ASIL-IS) and another method using a shared stable isotope from another analyte for internal standardization (SSIL-IS). Variance in inter-specimen matrix effect, without the use of a matrix normalization method, was studied by UPLC-MS-MS analysis of 338 urine donor samples and showed >200% variation in ion response for some analytes. Matrix normalization methods were evaluated for precision, accuracy, calibration, multi-matrix recovery and positive casework quantitation. Acceptable calibration and quality control criteria were achieved for all methods when calibrators and controls were prepared from the same urine matrix pool. Quantitative accuracy, determined by the addition of analytes to multi-donor urine pools at two concentration levels, resulted in acceptable percent relative standard deviation (%RSD) and bias for TAC and ASIL-IS methods. SSIL-IS method quantitations in analyte-supplemented donor pools revealed a %RSD ranging from 20% to 60% for >30% of the analytes and a method bias that ranged up to 87%, with a differential matrix effect on analyte and shared internal standard accounting for the imprecision and bias. Analyte quantitation in 162 authentic case samples showed close agreement for TAC and ASIL-IS methods, with greater variance in the SSIL-IS method. The study demonstrates effective matrix normalization by ASIL-IS and TAC methods and a matrix-caused bias in the SSIL-IS method.
Topics: Chromatography, High Pressure Liquid; Chromatography, Liquid; Pharmaceutical Preparations; Substance Abuse Detection; Tandem Mass Spectrometry
PubMed: 34013336
DOI: 10.1093/jat/bkab052 -
Methods in Molecular Biology (Clifton,... 2020The greatest advantage of frontal affinity chromatography (FAC) is that the analyte concentration does not need to be taken into consideration, and this renders FAC an... (Review)
Review
The greatest advantage of frontal affinity chromatography (FAC) is that the analyte concentration does not need to be taken into consideration, and this renders FAC an extremely favorable analytical tool for weak interactions. In this short review, we propose a straightforward explanation of the underlying mechanism. When FAC is performed using analyte solutions at relatively high concentrations, concentration-dependent retardation is observed due to competition among analyte molecules, and the elution volume changes depending on the degree of saturation of the immobilized ligand.However, when the analyte concentration is very low, no competition occurs among the analytes, and the elution volume reaches a constant value, which reflects the proportion of bound state to free state of a single analyte molecule. Therefore, the binding strength can be determined using a minimum analyte concentration.
Topics: Biomedical Research; Chromatography, Affinity; Lectins; Ligands; Polysaccharides; Protein Binding
PubMed: 32306312
DOI: 10.1007/978-1-0716-0430-4_4 -
Annals of Biomedical Engineering Oct 2020Molecular diagnostics have traditionally relied on discrete biological substances as diagnostic markers. In recent years however, advances in on-chip biomarker screening... (Review)
Review
Molecular diagnostics have traditionally relied on discrete biological substances as diagnostic markers. In recent years however, advances in on-chip biomarker screening technologies and data analytics have enabled signature-based diagnostics. Such diagnostics aim to utilize unique combinations of multiple biomarkers or diagnostic 'fingerprints' rather than discrete analyte measurements. This approach has shown to improve both diagnostic accuracy and diagnostic specificity. In this review, signature-based diagnostics enabled by microfluidic and micro-/nano- technologies will be reviewed with a focus on device design and data analysis pipelines and methodologies. With increasing amounts of data available from microfluidic biomarker screening, isolation, and detection platforms, advanced data handling and analytics approaches can be employed. Thus, current data analysis approaches including machine learning and recent advances with image processing, along with potential future directions will be explored. Lastly, the needs and gaps in current literature will be elucidated to inform future efforts towards development of molecular diagnostics and biomarker screening technologies.
Topics: Animals; Biomarkers; Humans; Lab-On-A-Chip Devices; Machine Learning; Microfluidic Analytical Techniques; Molecular Diagnostic Techniques
PubMed: 32816167
DOI: 10.1007/s10439-020-02593-y -
Analytical Chemistry May 2022High-throughput surface-enhanced Raman scattering (SERS) reader, especially for liquid sample testing, is of great significance and huge demand in biology, environment,...
High-throughput surface-enhanced Raman scattering (SERS) reader, especially for liquid sample testing, is of great significance and huge demand in biology, environment, and other analytical fields. Inspired by the principle of microplate reader, herein, we developed a microplate-SERS reader for semiautomatic and high-throughput assays by virtue of three-dimensional liquid interfacial arrays (LIAs). For the first time, the formation of LIA in oil-in-water state, water-in-oil state, and two-dimensional plane state is realized by operating the hydrophilicity (contact angle) of the container. Through the force analysis of LIA, the effect of organic (O) phase density on the relative position of LIA was quantified. In addition, the optimized reader offers fast and continuous semiautomatic detection of 12 samples below 10 min with great signal reproducibility (calibration with the characteristic peak of O phase as the internal standard). The isolated wells in the microplate prevent analyte cross talk, allowing accurate quantification of each sample. Multiplex analysis capability highlights that this reader has the ability of rapid identification and quantification of samples containing various analytes and concentrations. The results demonstrate high-resolution dual and triple analyte detection with fully preserved signal and Raman features of individual analytes in a mixture, which implies that it also has excellent anticounterfeiting applications. This microplate-SERS reader combines the superior advantages of the LIA, microplate, and SERS techniques to retrieve the molecular vibrational fingerprints of various chemicals in complex media.
Topics: Hydrophobic and Hydrophilic Interactions; Reproducibility of Results; Spectrum Analysis, Raman; Water
PubMed: 35581026
DOI: 10.1021/acs.analchem.2c00252 -
Analytica Chimica Acta Aug 2017Multi-energy calibration (MEC) is a novel strategy that explores the capacity of several analytes of generating analytical signals at many different wavelengths...
Multi-energy calibration (MEC) is a novel strategy that explores the capacity of several analytes of generating analytical signals at many different wavelengths (transition energies). Contrasting with traditional methods, which employ a fixed transition energy and different analyte concentrations to build a calibration plot, MEC uses a fixed analyte concentration and multiple transition energies for calibration. Only two calibration solutions are required in combination with the MEC method. Solution 1 is composed of 50% v v sample and 50% v v of a standard solution containing the analytes. Solution 2 has 50% v v sample and 50% v v blank. Calibration is performed by running each solution separately and monitoring the instrument response at several wavelengths for each analyte. Analytical signals from solutions 1 and 2 are plotted on the x-axis and y-axis, respectively, and the analyte concentration in the sample is calculated from the slope of the resulting calibration curve. The method has been applied to three different atomic spectrometric techniques (ICP OES, MIP OES and HR-CS FAAS). Six analytes were determined in complex samples (e.g. green tea, cola soft drink, cough medicine, soy sauce, and red wine), and the results were comparable with, and in several cases more accurate than, values obtained using the traditional external calibration, internal standardization, and standard additions methods. MEC is a simple, fast and efficient matrix-matching calibration method. It may be applied to any technique capable of simultaneous or fast sequential monitoring of multiple analytical signals.
Topics: Antitussive Agents; Calibration; Carbonated Beverages; Reference Standards; Soy Foods; Spectrophotometry, Atomic; Tea; Wine
PubMed: 28734363
DOI: 10.1016/j.aca.2017.06.040 -
Sports Medicine (Auckland, N.Z.) Mar 2017Physical inactivity is one of the most prevalent risk factors for non-communicable diseases in the world. A fundamental barrier to enhancing physical activity levels and... (Review)
Review
Physical inactivity is one of the most prevalent risk factors for non-communicable diseases in the world. A fundamental barrier to enhancing physical activity levels and decreasing sedentary behavior is limited by our understanding of associated measurement and analytical techniques. The number of analytical techniques for physical activity measurement has grown significantly, and although emerging techniques may advance analyses, little consensus is presently available and further synthesis is therefore required. The objective of this review was to identify the accuracy of emerging analytical techniques used for physical activity measurement in humans. We conducted a search of electronic databases using Web of Science, PubMed, and Google Scholar. This review included studies written in English and published between January 2010 and December 2014 that assessed physical activity using emerging analytical techniques and reported technique accuracy. A total of 2064 papers were initially retrieved from three databases. After duplicates were removed and remaining articles screened, 50 full-text articles were reviewed, resulting in the inclusion of 11 articles that met the eligibility criteria. Despite the diverse nature and the range in accuracy associated with some of the analytic techniques, the rapid development of analytics has demonstrated that more sensitive information about physical activity may be attained. However, further refinement of these techniques is needed.
Topics: Cell Phone; Exercise; Humans; Technology; Wearable Electronic Devices
PubMed: 27402456
DOI: 10.1007/s40279-016-0585-y