Search

This work reports the development and application of a disposable amperometric sensor built on magnetic microcarriers coupled to an Express PCR strategy to amplify a specific DNA fragment of the chloroplast trnH-psbA. The procedure involves the selective capture of a 68-mer synthetic target DNA (or unmodified PCR products) through sandwich hybridization with RNA capture probe-modified streptavidin MBs and RNA signaling probes, labeled using antibodies specific to the heteroduplexes and secondary antibodies tagged with horseradish peroxidase. Amperometric measurements were performed on screen-printed electrodes using the H 2 O 2 /hydroquinone system. Achieving a LOD of 3 pM for the synthetic target, it was possible to detect 2.5 pg of peanut DNA and around 10 mg kg -1 of peanut in binary mixtures (defatted peanut flours prepared in spelt wheat). However, the detectability decreased between 10 and 1000 times in processed samples depending on the treatment. The Express PCR-bioplatform was applied to the detection of peanut traces in foodstuff., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Although blood autoantibodies were initially associated with autoimmune diseases, multiple evidence have been accumulated showing their presence in many types of cancer. This has opened their use in clinics, since cancer autoantibodies might be useful for early detection, prognosis, and monitoring of cancer patients. In this review, we discuss the different techniques available for their discovery and validation. Additionally, we discuss here in detail those autoantibody panels verified in at least two different reports that should be more likely to be specific of each of the four most incident cancers. We also report the recent developed kits for breast and lung cancer detection mostly based on autoantibodies and the identification of novel therapeutic targets because of the screening of the cancer humoral immune response. Finally, we discuss unsolved issues that still need to be addressed for the implementation of cancer autoantibodies in clinical routine for cancer diagnosis, prognosis, and/or monitoring., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Montero-Calle, Garranzo-Asensio, Moreno-Casbas, Campuzano and Barderas.)

Cataracts and glaucoma account for a high percentage of vision loss and blindness worldwide. Small extracellular vesicles (sEVs) are released into different body fluids, including the eye's aqueous humor. Information about their proteome content and characterization in ocular pathologies is not yet well established. In this study, aqueous humor sEVs from healthy individuals, cataracts, and glaucoma patients were studied, and their specific protein profiles were characterized. Moreover, the potential of identified proteins as diagnostic glaucoma biomarkers was evaluated. The protein content of sEVs from patients' aqueous humor with cataracts and glaucoma compared to healthy individuals was analyzed by quantitative proteomics. Validation was performed by western blot (WB) and ELISA. A total of 828 peptides and 192 proteins were identified and quantified. After data analysis with the R program, 8 significantly dysregulated proteins from aqueous humor sEVs in cataracts and 16 in glaucoma showed an expression ratio ≥ 1.5. By WB and ELISA using directly aqueous humor samples, the dysregulation of 9 proteins was mostly confirmed. Importantly, GAS6 and SPP1 showed high diagnostic ability of glaucoma, which in combination allowed for discriminating glaucoma patients from control individuals with an area under the curve of 76.1% and a sensitivity of 65.6% and a specificity of 87.7%.

A trendsetting direct competitive-based biosensing tool has been developed and implemented for the determination of the polyunsaturated fatty acid arachidonic acid (ARA), a highly significant biological regulator with decisive roles in viral infections. The designed methodology involves a competitive reaction between the target endogenous ARA and a biotin-ARA competitor for the recognition sites of anti-ARA antibodies covalently attached to the surface of carboxylic acid-coated magnetic microbeads (HOOC-MµBs), followed by the enzymatic label of the biotin-ARA residues with streptavidin-horseradish peroxidase (Strep-HRP) conjugate. The resulting bioconjugates were magnetically trapped onto the sensing surface of disposable screen-printed carbon transducers (SPCEs) to monitor the extent of the biorecognition reaction through amperometry. The operational functioning of the exhaustively optimized and characterized immunosensing bioplatform was highly convenient for the quantitative determination of ARA in serum samples from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2-) and respiratory syncytial virus (RSV)-infected individuals in a rapid, affordable, trustful, and sensitive manner., (© 2024. The Author(s).)

This work presents the first bioplatform described to date for the determination of galactose-α-1,3-galactose (α-Gal), a non-primate mammalian oligosaccharide responsible for almost all cases of red meat allergy. The bioplatform is based on the implementation of an indirect competitive immunoassay and enzymatic labeling with the enzyme horseradish peroxidase (HRP) built on the surface of magnetic microparticles (MBs) and amperometric transduction on screen-printed carbon electrodes (SPCEs) using the H 2 O 2 /hydroquinone (HQ) system. The target α-Gal competed with biotinylated α-Gal immobilized on the surface of neutravidin-modified MBs for the limited immunorecognition sites of a detection antibody enzymatically labeled with an HRP-conjugated secondary antibody. The resulting magnetic immunoconjugates were trapped on the surface of the SPCE working electrode and amperometric transduction was performed, providing a cathodic current variation inversely proportional to the concentration of α-Gal in the analyzed sample. The developed biotool was optimized, characterized and applied with satisfactory results to the determination of the target allergen in different samples of raw and processed meats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Electrochemical biosensing continues to advance tirelessly, overcoming barriers that have kept it from leaving research laboratories for many years. Among them, its compromised performance in complex biological matrices due to fouling or receptor stability issues, the limitations in determining toxic and small analytes, and its use, conditioned to the commercial availability of commercial receptors and the exploration of natural molecular interactions, deserved to be highlighted. To address these challenges, in addition to the intrinsic properties of electrochemical biosensing, its coupling with biomimetic materials has played a fundamental role, among which bioinspired phage and peptide probes stand out. The versatility in design and employment of these probes has opened an unimaginable plethora of possibilities for electrochemical biosensing, improving their performance far beyond the development of highly sensitive and selective devices. The state of the art offers robust electroanalytical biotools, capable of operating in complex samples and with exciting opportunities to discover and determine targets regardless of their toxicity and size, the commercial availability of bioreceptors, and prior knowledge of molecular interactions. With all this in mind, this review offers a panoramic, novel, and updated vision of both the tremendous advances and opportunities offered by the combination of electrochemical biosensors with bioinspired phage and peptide probes and the challenges and research efforts that are envisioned in the immediate future., (© 2024. The Author(s).)

Alzheimer's disease (AD), in addition to being the most common cause of dementia, is very difficult to diagnose, with the 42-amino acid form of Aβ (Aβ-42) being one of the main biomarkers used for this purpose. Despite the enormous efforts made in recent years, the technologies available to determine Aβ-42 in human samples require sophisticated instrumentation, present high complexity, are sample and time-consuming, and are costly, highlighting the urgent need not only to develop new tools to overcome these limitations but to provide an early detection and treatment window for AD, which is a top-challenge. In recent years, micromotor (MM) technology has proven to add a new dimension to clinical biosensing, enabling ultrasensitive detections in short times and microscale environments. To this end, here an electrochemical immunoassay based on polypyrrole (PPy)/nickel (Ni)/platinum nanoparticles (PtNPs) MM is proposed in a pioneering manner for the determination of Aβ-42 in left prefrontal cortex brain tissue, cerebrospinal fluid, and plasma samples from patients with AD. MM combines the high binding capacity of their immunorecognition external layer with self-propulsion through the catalytic generation of oxygen bubbles in the internal layer due to decomposition of hydrogen peroxide as fuel, allowing rapid bio-detection (15 min) of Aβ-42 with excellent selectivity and sensitivity (LOD = 0.06 ng/mL). The application of this disruptive technology to the analysis of just 25 μL of the three types of clinical samples provides values concordant with the clinical values reported, thus confirming the potential of the MM approach to assist in the reliable, simple, fast, and affordable diagnosis of AD by determining Aβ-42., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In the era that we seek personalization in material things, it is becoming increasingly clear that the individualized management of medicine and nutrition plays a key role in life expectancy and quality of life, allowing participation to some extent in our welfare and the use of societal resources in a rationale and equitable way. The implementation of precision medicine and nutrition are highly complex challenges which depend on the development of new technologies able to meet important requirements in terms of cost, simplicity, and versatility, and to determine both individually and simultaneously, almost in real time and with the required sensitivity and reliability, molecular markers of different omics levels in biofluids extracted, secreted (either naturally or stimulated), or circulating in the body. Relying on representative and pioneering examples, this review article critically discusses recent advances driving the position of electrochemical bioplatforms as one of the winning horses for the implementation of suitable tools for advanced diagnostics, therapy, and precision nutrition. In addition to a critical overview of the state of the art, including groundbreaking applications and challenges ahead, the article concludes with a personal vision of the imminent roadmap., (© 2023. The Author(s).)

This work reports the first electrochemical bioplatforms developed for the determination of the total contents of either target miRNA or methylated target miRNA. The bioplatforms are based on the hybridization of the target miRNA with a synthetic biotinylated DNA probe, the capture of the formed DNA/miRNA heterohybrids on the surface of magnetic microcarriers, and their recognition with an antibody selective to these heterohybrids or to the N 6 -methyladenosine (m6A) epimark. The determination of the total or methylated target miRNA was accomplished by labeling such secondary antibodies with the horseradish peroxidase (HRP) enzyme. In both cases, amperometric transduction was performed on the surface of disposable electrodes after capturing the resulting HRP-tagged magnetic bioconjugates. Because of their increasing relevance in colorectal cancer (CRC) diagnosis and prognosis, miRNA let-7a and m6A methylation were selected. The proposed electrochemical bioplatforms showed attractive analytical and operational characteristics for the determination of the total and m6A-methylated target miRNA in less than 75 min. These bioplatforms, innovative in design and application, were applied to the analysis of total RNA samples extracted from cultured cancer cells with different metastatic profiles and from paired healthy and tumor tissues of patients diagnosed with CRC at different stages. The obtained results demonstrated, for the first time using electrochemical platforms, the potential of interrogating the target miRNA methylation level to discriminate the metastatic capacities of cancer cells and to identify tumor tissues and, in a pioneering way, the potential of the m6A methylation in miRNA let-7a to serve as a prognostic biomarker for CRC.

The impact of ammonia on anaerobic digestion performance and microbial dynamics has been extensively studied, but the concurrent effect of anions brought by ammonium salt should not be neglected. This paper studied this effect using metabolomics and a time-course statistical framework. Metabolomics provides novel perspectives to study microbial processes and facilitates a more profound understanding at the metabolic level. The advanced statistical framework enables deciphering the complexity of large metabolomics data sets. More specifically, a series of lab-scale batch reactors were set up with different ammonia sources added. Samples of nine time points over the degradation were analyzed with liquid chromatography-mass spectrometry. A filtering procedure was applied to select the promising metabolomic peaks from 1262 peaks, followed by modeling their intensities across time. The metabolomic peaks with similar time profiles were clustered, evidencing the correlation of different biological processes. Differential analysis was performed to seek the differences in metabolite dynamics caused by different anions. Finally, tandem mass spectrometry and metabolite annotation provided further information on the molecular structure and possible metabolic pathways. For example, the consumption of 5-aminovaleric acid, a short-chain fatty acid obtained from l-lysine degradation, was slowed down by phosphates. Overall, by investigating the effect of anions on anaerobic digestion, our study demonstrated the effectiveness of metabolomics in providing detailed information in a set of samples from different experimental conditions. With the statistical framework, the approach enables capturing subtle differences in metabolite dynamics between samples while accounting for the differences caused by time variations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This work reports the first electrochemical bioplatform developed for the determination of human endostatin (HE), a biomarker with recognized antiangiogenic potential whose elevated circulating levels have also been associated with the development of aggressive cancers. The developed electroanalytical biotool combines the benefits of using magnetic microparticles for the implementation of sandwich immunoassays and amperometric transduction on disposable carbon electrodes. A limit of detection (LOD) of 34.1 pg mL -1 for HE standards and a selectivity suitable for its foray into the clinical oncology area, are demonstrated. The determination of HE in clinical samples such as lysates and secretomes of colorectal cancer (CRC) cells, plasma, and tissue samples from patients with CRC in different stages, has been faced with satisfactory results showing the ability for discriminating the metastatic capabilities of cells and for identifying and staging CRC patients. The developed bioplatform allows precise quantitative determinations, requiring minimal pre-treatments and sample amounts in only 75 min. In addition, due to the instrumentation and the type of substrates used in the detection step, the biotool is compatible with implementation in multiplexed and/or point-of-need devices, features in which this bioplatform is advantageous with respect to the enzyme linked immunosorbent assay (ELISA) or immunoblotting technologies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Detecting overexpression of cancer biomarkers is an excellent tool for diagnostic/prognostic and follow-up of patients with cancer or their response to treatment. This work illustrates the relevance of interrogating the levels of T-cell immunoglobulin and mucin domain 1 (TIM-1) protein as a diagnostic/prognostic biomarker of high-prevalence breast and lung cancers by using an amperometric disposable magnetic microparticles-assisted immunoplatform. The developed method integrates the inherent advantages of carboxylic acid-functionalized magnetic beads (HOOC-MBs) as pre-concentrator support and the amperometric transduction at screen-printed carbon electrodes (SPCEs). The immunoplatform involves a sandwich-type immunoassay assembled on HOOC-MBs through the specific capture/labeling of TIM-1 using capture antibodies and horseradish peroxidase (HRP)-conjugated biotinylated detection antibodies as biorecognition elements. The magnetic immunoconjugates were confined onto the working electrode (WE) surface of the SPCEs for amperometric detection using the hydroquinone/hydrogen peroxide/HRP (HQ/H 2 O 2 /HRP) redox system. The method allows the selective detection of TIM-1 protein over the 87-7500 pg mL -1 concentration range in only 45 min, with a limit of detection of 26 pg mL -1 . The developed bioplatform was successfully applied to the analysis of breast and lung cancer cell extracts, providing the first quantitative results of the target glycoprotein in these types of samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The subfamily Triatominae includes a group of hematophagous insects, vectors of the parasite Trypanosoma cruzi, which is the etiological agent of Chagas disease, also known as American trypanosomiasis. Triatomines occur in the Old and New World and occupy diverse habitats including tropical and temperate areas. Some studies suggest the distributions of triatomines group into three or four regions. This study objectively determined bioregions focused specifically on New World Triatominae, using clustering and ordination analysis. We also identified indicator species by bioregion and investigated relationships among bioregions and environmental variables using redundancy analysis and multivariate regression trees. We delineated seven bioregions specific to Triatominae and linked each with indicator species. This result suggests more biogeographical structure exists than was revealed in earlier studies that were more general, subjective, and based on older taxonomic and distributional information. Precipitation, elevation, and vegetation were important variables in the delimitating bioregions. This implies that more detailed study of how these factors influence triatomine distributions could benefit understanding of how Chagas disease is spread., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)