Enhancing the lateral-flow immunoassay for viral detection using an aqueous two-phase micellar system

Availability of a rapid, accurate, and reliable point-of-care (POC) device for detection of infectious agents and pandemic pathogens, such as swine-origin influenza A (H1N1) virus, is crucial for effective patient management and outbreak prevention. Due to its ease of use, rapid processing, and minimal power and laboratory equipment requirements, the lateral-flow (immuno)assay (LFA) has gained much attention in recent years as a possible solution. However, since the sensitivity of LFA has been shown to be inferior to that of the gold standards of pathogen detection, namely cell culture and real-time PCR, LFA remains an ineffective POC assay for preventing pandemic outbreaks. A practical solution for increasing the sensitivity of LFA is to concentrate the target agent in a solution prior to the detection step. In this study, an aqueous two-phase micellar system comprised of the nonionic surfactant Triton X-114 was investigated for concentrating a model virus, namely bacteriophage M13 (M13), prior to LFA. The volume ratio of the two coexisting micellar phases was manipulated to concentrate M13 in the top, micelle-poor phase. The concentration step effectively improved the M13 detection limit of the assay by tenfold from 5 × 108 plaque forming units (pfu)/mL to 5 × 107 pfu/mL. In the future, the volume ratio can be further manipulated to yield a greater concentration of a target virus and further decrease the detection limits of the LFA. Figure A schematic representation of concentrating viruses with an aqueous two-phase micellar system containing Triton X-114 surfactant prior to the detection of the virus through the lateral-flow immunoassa

Greenness assessment of microextractiontechniques in therapeutic drug monitoring: supplementary materials

Aim: In this study, we evaluated the greenness and whiteness scores for microextraction techniques usedin therapeutic drug monitoring. Additionally, the cons and pros of each evaluated method and theirimpacts on the provided scores are also discussed. Materials & methods: The Analytical Greenness SamplePreparation metric tool and white analytical chemistry principles are used for related published works(2007–2023). Results & conclusion: This study provided valuable insights for developing methods basedon microextraction techniques with a balance in greenness and whiteness areas. Some methods basedon a specific technique recorded higher scores, making them suitable candidates as green analyticalapproaches, and some others achieved high scores both in green and white areas with a satisfactorybalance between principles.</p

Recent molecularly imprinted polymers applications in bioanalysis.

Molecular imprinted polymers (MIPs) as extraordinary compounds with unique features have presented a wide range of applications and benefits to researchers. In particular when used as a sorbent in sample preparation methods for the analysis of biological samples and complex matrices. Its application in the extraction of medicinal species has attracted much attention and a growing interest. This review focus on articles and research that deals with the application of MIPs in the analysis of components such as biomarkers, drugs, hormones, blockers and inhibitors, especially in biological matrices. The studies based on MIP applications in bioanalysis and the deployment of MIPs in high-throughput settings and optimization of extraction methods are presented. A review of more than 200 articles and research works clearly shows that the superiority of MIP techniques lies in high accuracy, reproducibility, sensitivity, speed and cost effectiveness which make them suitable for clinical usage. Furthermore, this review present MIP-based extraction techniques and MIP-biosensors which are categorized on their classes based on common properties of target components. Extraction methods, studied sample matrices, target analytes, analytical techniques and their results for each study are described. Investigations indicate satisfactory results using MIP-based bioanalysis. According to the increasing number of studies on method development over the last decade, the use of MIPs in bioanalysis is growing and will further expand the scope of MIP applications for less studied samples and analytes

A multi-enzyme model for pyrosequencing

Pyrosequencing is a DNA sequencing technique based on sequencing-by-synthesis enabling rapid real-time sequence determination. This technique employs four enzymatic reactions in a single tube to monitor DNA synthesis. Nucleotides are added iteratively to the reaction and in case of incorporation, pyrophosphate (PPi) is released. PPi triggers a series of reactions resulting in production of light, which is proportional to the amount of DNA and number of incorporated nucleotides. Generated light is detected and recorded by a detector system in the form of a peak signal, which reflects the activity of all four enzymes in the reaction. We have developed simulations to model the kinetics of the enzymes. These simulations provide a full model for the Pyrosequencing four-enzyme system, based on which the peak height and shape can be predicted depending on the concentrations of enzymes and substrates. Simulation results are shown to be compatible with experimental data. Based on these simulations, the rate-limiting steps in the chain can be determined, and K(M) and k(cat) of all four enzymes in Pyrosequencing can be calculated