Bioanalysis Research Articles

Iron oxide nanozymes as versatile analytical tools: an overview of their application as detection technique.

Iron oxide nanozymes (IONzymes) have become fundamental components in various analyte detection methodologies such as colorimetric, electrochemistry, fluorescence and luminescence. Their tunability, stability and the possibility of modification, alongside their ability to mimic the catalytic properties of natural enzymes like peroxidase, render them invaluable in analytical chemistry. This review explores the diverse applications of IONzymes across analytical chemistry, with a particular highlighting on their roles in different detection techniques and their potential in biomedical and diagnostic applications. This information would be valuable for researchers and practitioners in the fields of analytical chemistry, biochemistry, biotechnology and materials science who are interested in applying IONzymes in their work. In essence, this review article on iron oxide nanozymes in analytical chemistry would serve as a valuable resource for researchers, educators and industry professionals, offering insights, guidance and inspiration for further study and application of this promising class of nanomaterials.

Enhanced Green Fluorescent Protein Streaming Dielectrophoresis in Insulator-Based Microfluidic Devices.

There is tantalizing evidence that proteins can be accurately and selectively manipulated by higher order electric field effects within microfluidic devices. The accurate and precise manipulation of proteins in these platforms promises to disrupt and revolutionize many fields, most notably analytical biochemistry. Several lines of experimental evidence suggest much higher forces are generated compared to those calculated from traditional theories and those higher forces arise from subtle structural features of the proteins providing selectivity. New theories reflect some of the experimental evidence in the magnitude of the force predicted and inclusion of subtle structural features absent in traditional continuum theory. Unfortunately, the experimental evidence is largely exploratory in nature and lacks one or more important elements that prevents a clear interpretation and comparison to not only the other existing data, but also quantitative comparison to the evolving theoretical descriptions. Here, a clear and interpretable experimental system is presented that quantitatively determines the dielectrophoretic susceptibility of unlabeled, unaggregated native-structure protein molecules that are exposed to modest electric fields (105-106V/m) for short periods of time (∼5ms) without significant increases in local concentration. The platform uses sub-nanogram quantities of protein, the probed volume upon determination is a few picoliters, and the total analysis time is 10 s.

Thermal decomposition and atmospheric pressure chemical ionization of alanine using ion mobility spectrometry and computational study

This study investigates the impact of thermal decomposition on the ion mobility spectrum of L-alanine using ion mobility spectrometry (IMS) and computational methods. By employing a post-injection delay system, we examined the evolution of ion peaks corresponding to thermal decomposition products and their interaction with protonated alanine. Experimental results revealed that the observed ion mobility spectra predominantly feature protonated isomers and adduct ions. Computational analysis using Density Functional Theory (DFT) predicted the thermodynamically favored structures and stabilities of these products. Findings indicate that protonation at the nitrogen site in alanine is more stable than at the oxygen site, and observed peaks correspond to protonated isomers and adducts formed with ammonium ions. Further investigations showed that thermal decomposition of alanine generates ammonia, contributing to the formation of new adduct ions. This research provides new insights into the behavior of amino acids under thermal conditions with implications for analytical chemistry and biochemistry.

Enzyme-Modified Microelectrode for Simultaneous Local Measurements of O2 and pH.

The use of miniaturized probes opens a new dimension in the analysis of (bio)chemical processes, enabling the possibility to perform measurements with local resolution. In addition, multiparametric measurements are highly valuable for a holistic understanding of the investigated process. Therefore, different strategies have been suggested for simultaneous local measurements of various parameters. Electroanalytical methods are a powerful strategy in this direction. However, they have been mainly restricted to coupling concurrent independent measurements with different miniaturized probes. Here, we present an enzymatic microbiosensor for the simultaneous detection of O2 and pH. The sensing strategy is based on the pH-dependent bioelectrocatalytic process associated with O2 reduction at a gold microelectrode modified with a multicopper oxidase. After initial investigations of the bioelectrocatalytic reaction over gold macroelectrodes, the fabrication and characterization of micrometer-sized probes are presented. The microbioelectrode exhibits a linear current increase with O2 concentration extending to 17.2 mg L-1, with a sensitivity of (5.56 ± 0.13) nA L mg-1 and a limit of detection of (0.5 ± 0.3) mg L-1. Moreover, a linear response allowing pH detection is obtained between pH 5.2 and 7.5 with a slope of -(47 ± 8) mV per pH unit. In addition, two proof-of-concept analytical examples are shown, demonstrating the capability of the developed sensing system for simultaneous local measurements of O2 and pH. Compared with other miniaturized probes reported before for simultaneous detection, our strategy stands out as the two investigated parameters are acquired from the very same measurement. This strategy greatly simplifies the analytical setup and for the first time provides truly simultaneous local detection in the micrometer scale.

Review on Green Bioanalytical Chemistry with Sustainable Approaches in Method Development: Unveiling the Crucial Role of Sustainable Bioanalysis in the Future of Chemistry

Green bioanalytical chemistry, with its focus on incorporating sustainable practices into developing bioanalytical methods, has the potential to significantly reduce the environmental impact of laboratory activities. This approach, while maintaining the high standards required for analytical precision and accuracy, includes key strategies such as reducing hazardous chemicals, optimizing energy use, and implementing waste-reduction practices. This review highlights recent advancements in green bioanalytical chemistry, including green solvent systems, miniaturized techniques, and eco-friendly analytical platforms. We discuss the benefits, such as reduced environmental pollution and improved resource efficiency, challenges, and future perspectives of integrating green principles into bioanalytical method development, emphasizing the balance between sustainability and analytical performance.

Optical Image Sensors for Smart Analytical Chemiluminescence Biosensors.

Optical biosensors have emerged as a powerful tool in analytical biochemistry, offering high sensitivity and specificity in the detection of various biomolecules. This article explores the advancements in the integration of optical biosensors with microfluidic technologies, creating lab-on-a-chip (LOC) platforms that enable rapid, efficient, and miniaturized analysis at the point of need. These LOC platforms leverage optical phenomena such as chemiluminescence and electrochemiluminescence to achieve real-time detection and quantification of analytes, making them ideal for applications in medical diagnostics, environmental monitoring, and food safety. Various optical detectors used for detecting chemiluminescence are reviewed, including single-point detectors such as photomultiplier tubes (PMT) and avalanche photodiodes (APD), and pixelated detectors such as charge-coupled devices (CCD) and complementary metal-oxide-semiconductor (CMOS) sensors. A significant advancement discussed in this review is the integration of optical biosensors with pixelated image sensors, particularly CMOS image sensors. These sensors provide numerous advantages over traditional single-point detectors, including high-resolution imaging, spatially resolved measurements, and the ability to simultaneously detect multiple analytes. Their compact size, low power consumption, and cost-effectiveness further enhance their suitability for portable and point-of-care diagnostic devices. In the future, the integration of machine learning algorithms with these technologies promises to enhance data analysis and interpretation, driving the development of more sophisticated, efficient, and accessible diagnostic tools for diverse applications.

Accurate numerical prototypes of microfluidic droplet generators with open source tools

Droplet-based microfluidics gained significant attention for its high technological impact in various fields like (bio)analysis and (bio)synthesis. Precise and controlled droplet size is critical, for the encapsulated products, or the yield of chemical reactions. In a broad range of experimental parameters, the understanding of how droplets form, interact and move with accurate predictive models is crucial. In this work, numerical prototypes of droplet generators were made with Basilisk, an open source software for solving partial differential equations on adaptive Cartesian meshes including grid adaptation and scalability for High-Performance Computing (HPC). This research aims to analyze and compare the obtained droplets against existing experimental data. The evaluation involves qualitative and quantitative comparisons, considering various channel geometries, flow rates, and rheological conditions. The validation of the proposed tool in terms of accuracy and computational performance, enable us to offer to the microfluidics community a reliable tool to design and optimize droplet generators.

Atypical applications of transverse diffusion of laminar flow profiles methodology for in-capillary reactions in capillary electrophoresis.

Capillary electrophoresis (CE) is a powerful separation technique offering quick and efficient analyses in various fields of bioanalytical chemistry. It is characterized by many well-known advantages, but one, which is perhaps the most important for this application field, is somewhat overlooked. It is the possibility to perform chemical and biochemical reactions at the nL scale inside the separation capillary. There are two basic formats applicable for this purpose, heterogeneous and homogeneous. In the former, one reactant is immobilized onto a particle or monolithic support or directly on the capillary wall, and the other is injected. In the latter, the reactant mixing inside a capillary is based on electromigration or diffusion. One of the diffusion-based methodologies, termed Transverse Diffusion of Laminar Flow Profiles, is the subject of this review. Since most studies utilizing in-capillary reactions in CE focus on enzymes, which are being continuously and exhaustively reviewed, this review covers the atypical applications of this methodology, but still in the bioanalytical field. As can be seen from the demonstrated applications, they are not limited to reactions, but can also be utilized for other biochemical systems.

A multicriteria approach to quantify contaminant shives in industrial batches of flax fibres

Residual shives have a major impact on the quality and performance of flax textile and composite preforms. Quantifying the content of shives in batches of scutched flax fibres is a time-consuming and operator-dependent process. Although the shive content can be estimated from the chemical composition, our aim here is to explore a series of effective, reliable and complementary approaches to quantifying shives. Various methods are presented: microscopic observations, analytical biochemistry (monosaccharides, lignins), indirect methods (infrared spectroscopy) and dynamic morphological analysis (QICPIC). A reference standard was first analysed and then compared with batches of flax tow fibre of unknown shive content from current industrial production. This approach shows that calibration curves can be established by applying each selected method to batches with known fibre and shive content. In addition, a database was generated to determine the shive content of industrial batches using partial least squares (PLS) regression. Finally, a detailed study of shives in industrial batches is presented, comparing the different analytical methods.

Enhancing sensitivity towards electrochemical miRNA detection using an affordable paper-based strategy

In the era of liquid biopsy, microRNAs emerge as promising candidates for the early diagnosis and prognosis of cancer, offering valuable insights into the disease’s development. Among all the existing analytical approaches, even if traditional approaches such as the nucleic acid amplification ones have the advantages to be highly sensitive, they cannot be used at the point-of-care, while sensors might be poorly sensitive despite their portability. In order to improve the analytical performance of existing electroanalytical systems, we demonstrate how a simple chromatographic paper-based disk might be useful to rationally improve the sensitivity, depending on the number of preconcentration cycles. A paper-based electrochemical platform for miRNA detection has been developed by modifying a paper-based electrode with a methylene blue (MB)-modified single-stranded sequence (ssDNA) complementary to the chosen miRNA, namely miR-224 that is associated with lung cancer. A detection limit of ca. 0.6 nM has been obtained in spiked human serum samples. To further enhance the sensitivity, an external chromatographic wax-patterned paper-based disk has been adopted to preconcentrate the sample, and this has been demonstrated both in standard and in serum solutions. For each solution, three miR-224 levels have been preconcentrated, obtaining a satisfactory lowering detection limit of ca. 50 pM using a simple and sustainable procedure. This approach opens wide possibilities in the field of analytical and bioanalytical chemistry, being useful not only for electrochemistry but also for other architectures of detection and transduction.

Chemo-Enzymatic Generation of Highly Fluorescent Nucleoside Analogs Using Purine-Nucleoside Phosphorylase

Chemo-enzymatic syntheses of strongly fluorescent nucleoside analogs, potentially applicable in analytical biochemistry and cell biology are reviewed. The syntheses and properties of fluorescent ribofuranosides of several purine, 8-azapurine, and etheno-purine derivatives, obtained using various types of purine nucleoside phosphorylase (PNP) as catalysts, as well as α-ribose-1-phosphate (r1P) as a second substrate, are described. In several instances, the ribosylation sites are different to the canonical purine N9. Some of the obtained ribosides show fluorescence yields close to 100%. Possible applications of the new analogs include assays of PNP, nucleoside hydrolases, and other enzyme activities both in vitro and within living cells using fluorescence microscopy.

A multifunctional role for riboflavin in the yellow nectar of Capsicum baccatum and Capsicum pubescens.

A few Capsicum (pepper) species produce yellow-colored floral nectar, but the chemical identity and biological function of the yellow pigment are unknown. A combination of analytical biochemistry techniques was used to identify the pigment that gives Capsicum baccatum and Capsicum pubescens nectars their yellow color. Microbial growth assays, visual modeling, and honey bee preference tests for artificial nectars containing riboflavin were used to assess potential biological roles for the nectar pigment. High concentrations of riboflavin (vitamin B2) give the nectars their intense yellow color. Nectars containing riboflavin generate reactive oxygen species when exposed to light and reduce microbial growth. Visual modeling also indicates that the yellow color is highly conspicuous to bees within the context of the flower. Lastly, field experiments demonstrate that honey bees prefer artificial nectars containing riboflavin. Some Capsicum nectars contain a yellow-colored vitamin that appears to play roles in (1) limiting microbial growth, (2) the visual attraction of bees, and (3) as a reward to nectar-feeding flower visitors (potential pollinators), which is especially interesting since riboflavin is an essential nutrient for brood rearing in insects. These results cumulatively suggest that the riboflavin found in some Capsicum nectars has several functions.

Quasi-Bessel surface acoustic wave for dynamic acoustic manipulation

Acoustic manipulation using surface acoustic wave has aroused widespread interest in life sciences, biomedical, and bioanalytical chemistry. Acoustic manipulation for different applications requires different acoustic fields. Bessel beams are non-diffractive and re-constructable, bringing possibility and versatility of acoustic manipulation integrated on microfluidic chips. To date, there are a few studies on constructing Bessel surface acoustic waves. Moreover, there is still a lack of dynamic acoustic manipulation using Bessel surface acoustic waves propagating along a surface of piezoelectric substrate with simple and high-precision devices. Here, we design a device with two omnidirectional equifrequency interdigital transducers to form a quasi-Bessel surface acoustic wave by means of coherent interference. The proposed device avoids influences of anisotropy on its operating frequency, making its quasi-Bessel beam accurately and stably conform to the predetermined design acoustic field. This acoustic field could control micrometer to submicrometer particles and dynamically move particles along lateral direction and axial direction of the propagation of quasi-Bessel beam. A phenomenon similar to negative force appeared when the two-micron spherical particles were manipulated. The quasi-Bessel beam formed by our device can provide a versatile movement for on-chip acoustic manipulation.

Isolation of nucleic acids using liquid–liquid phase separation of pH-sensitive elastin-like polypeptides

Extraction of nucleic acids (NAs) is critical for many methods in molecular biology and bioanalytical chemistry. NA extraction has been extensively studied and optimized for a wide range of applications and its importance to society has significantly increased. The COVID-19 pandemic highlighted the importance of early and efficient NA testing, for which NA extraction is a critical analytical step prior to the detection by methods like polymerase chain reaction. This study explores simple, new approaches to extraction using engineered smart nanomaterials, namely NA-binding, intrinsically disordered proteins (IDPs), that undergo triggered liquid–liquid phase separation (LLPS). Two types of NA-binding IDPs are studied, both based on genetically engineered elastin-like polypeptides (ELPs), model IDPs that exhibit a lower critical solution temperature in water and can be designed to exhibit LLPS at desired temperatures in a variety of biological solutions. We show that ELP fusion proteins with natural NA-binding domains can be used to extract DNA and RNA from physiologically relevant solutions. We further show that LLPS of pH responsive ELPs that incorporate histidine in their sequences can be used for both binding, extraction and release of NAs from biological solutions, and can be used to detect SARS-CoV-2 RNA in samples from COVID-positive patients.

Systematic review on fingerprinting development to determine adulteration of Chinese herbal medicines

BackgroundIt has been a current research hospots using fingerprinting technology for quality control of Chinese herbal medicines (CHMs), which provides a scientific basis for establishment of overall quality control in accordance with the characteristics of CHMs. The fingerprinting technology for CHMs is diverse, and the research field covers many disciplines, such as analytical chemistry, pharmacology, pharmaceutics, biochemistry, and molecular biology. PurposeTo effectively understand the key areas and future directions of research regarding the fingerprint and adulteration of CHMs. Methods/resultsthis paper analyzed 879 articles in this field in the Web of Science Core Collection from 2000 to 2023 with CiteSpace and VOSviewer, and systematically assessed the research process, hotspots, topic distribution among disciplines, etc. The most prominent contributors of fingerprint and adulteration of CHMs research are mainly from China, India, the United States, England, and Brazil. The knowledge domains of fingerprint and adulteration of CHMs research focus mainly on the topics of molecular authentication, DNA barcoding, HPLC, near-infrared spectroscopy, manage data, chemometrics, and electrochemical fingerprinting. Most countries have recognized the pharmaceutical potential of natural products, and have paid more attention to the fingerprint and adulteration of CHMs in the past decade. Future the research tends to focus more on molecular identification and authentication, and electrochemical and chromatographic fingerprinting in controlling the adulteration of CHMs. ConclusionThis research provides a valuable reference for scholars in related fields to analyze existing research results, understand the development trend, and explore new research directions.

A Green Route for Sustainable Nanoporous Solid Acid Catalyst Synthesis Using Bio Template and Analysis of Its Progressive Transformation of CO2

Green chemistry approach is a most important area in the modern chemical world. The nano (meso) porous materials have the specific application in separation, adsorption and catalysis. A green template (Egg white) is used as a bio template for the synthesis of nanoporous material to replace the hazardous templates. It is a bio-degradable template; it does not create any environmental issues. The synthesized material is characterized by various spectroscopic techniques to confirm its structural formation. Based on pore size, the catalyst named as AlSiO4-14. The synthesized catalyst (AlSiO4-14) is active at 175oC. This low temperature activity will not produce coke formation at the same time it does not require any regeneration and the catalyst is continuously active for catalytic reactions. The catalytic activity of carbon dioxide decomposition is achieved at lower temperature. The complete carbon dioxide decomposition of AlSiO4-14 is 43 % is a great impact of the material.

Nanotechnology in Bioanalytical Chemistry

Nanotechnology in Bioanalytical Chemistry

Molecular dynamics simulations as a guide for modulating small molecule aggregation

Small colloidally aggregating molecules (SCAMs) can be problematic for biological assays in drug discovery campaigns. However, the self-associating properties of SCAMs have potential applications in drug delivery and analytical biochemistry. Consequently, the ability to predict the aggregation propensity of a small organic molecule is of considerable interest. Chemoinformatics-based filters such as ChemAGG and Aggregator Advisor offer rapid assessment but are limited by the assay quality and structural diversity of their training set data. Complementary to these tools, we explore here the ability of molecular dynamics (MD) simulations as a physics-based method capable of predicting the aggregation propensity of diverse chemical structures. For a set of 32 molecules, using simulations of 100 ns in explicit solvent, we find a success rate of 97% (one molecule misclassified) as opposed to 75% by Aggregator Advisor and 72% by ChemAGG. These short timescale MD simulations are representative of longer microsecond trajectories and yield an informative spectrum of aggregation propensities across the set of solutes, capturing the dynamic behaviour of weakly aggregating compounds. Implicit solvent simulations using the generalized Born model were less successful in predicting aggregation propensity. MD simulations were also performed to explore structure-aggregation relationships for selected molecules, identifying chemical modifications that reversed the predicted behaviour of a given aggregator/non-aggregator compound. While lower throughput than rapid cheminformatics-based SCAM filters, MD-based prediction of aggregation has potential to be deployed on the scale of focused subsets of moderate size, and, depending on the target application, provide guidance on removing or optimizing a compound’s aggregation propensity.Graphical

An Algebraic Blueprint for Predicting Turnover Numbers and Endpoints in Photocatalysis.

The front cover artwork is provided by the Institute of Analytical and Bioanalytical Chemistry and the Institute of Inorganic ChemistryI at Ulm University within the Collaborative Research Center TRR 234 CataLight. The image shows an algebraic approach to generically calculate and predict the turnover number (TON) and the endpoint of photocatalytic hydrogen gas evolution experiments. Read the full text of the Research Article at 10.1002/cphc.202300767.

Professor José Luis Capelo Martinez, a researcher who believes that science and technology have a direct and tangible impact on human well-being kindly granted BrJAC an interview

J. L. Capelo, PhD, gets his bachelor’s degree in chemistry by the University of Santiago de Compostela (Spain), his doctorate in Analytical Chemistry by University of Vigo, UVIGO (Spain, award to the best doctoral thesis 2002) and his Post-Doc from the Instituto Superior Técnico de Lisboa (Portugal). His academic career comprises assistant to staff and lecturer at the UVIGO; research fellow at the Chemistry Department of the New University of Lisbon, CD-FCT-UNL, research fellow at the CDUVIGO, and assistant professor at the CD-FCT- UNL. Currently he is Associate Professor at the CD-FCT-UNL. Dr. Capelo is co-head of the bioscopegroup (www.bioscopegroup.org.) and his CV comprises (up to October 2023): 290 manuscripts; 250 congress communications (orals and posters); 23 projects; 2 Patents, 1 license agreement and 3 books (1 authored and 2 edited). He has chaired 65 international conferences and is presently involved in the direction of 7. He was a member of the advisory board of Talanta from 2006 to 2014 and is Editor in Chief of the on-line Journal JIOMICS (www.JIOMICS.com) since its creation in 2011. He is presently mentoring or co-mentoring a total of 3 doctoral theses, and he has mentored 3 post-doctoral grants, 10 doctoral grants, 9 masters and 8 final projects. His current research interest is devoted to developing new methodological approaches in personalised medicine using new proteomics approaches and unravelling bacterial resistance to antibiotics. He is a Fellow Member of the Royal Society of Chemistry, member of the American Chemical Society and member of the Portuguese Society of Chemistry. H index 45 (Scopus Scholar). 8300 Citations. His skills include sampling and sample treatment for trace metals; metal speciation, proteomics, biomarker discovery; food chemistry; and development and validation of analytical procedures. Analytical techniques: HPLC-ICP-MS, ET-AAS, F-AAS, CVAAS, HG- AAS, HG-AFS, MALDI-TOF-MS/MS, RP-HPLC-ESI-IT-MS/MS. Teaching (theory and laboratory) in Analytical Biochemistry, Proteomics, and related disciplines. H index 40, circa 8000 citations. Awards: Best 2002 Doctoral Thesis in Chemistry. University of Vigo. Spain. Rainbow Prize 2017.