Mid-infrared spectroscopy is a sensitive and selective technique for probing molecules in the gas or liquid phase. Investigating chemical reactions in bio-medical applications such as drug production is recently gaining particular interest. However, monitoring dynamic processes in liquids is commonly limited to bulky systems and thus requires time-consuming offline analytics. In this work, we show a next-generation, fully-integrated and robust chip-scale sensor for online measurements of molecule dynamics in a liquid solution. Our fingertip-sized device utilizes quantum cascade technology, combining the emitter, sensing section and detector on a single chip. This enables real-time measurements probing only microliter amounts of analyte in an in situ configuration. We demonstrate time-resolved device operation by analyzing temperature-induced conformational changes of the model protein bovine serum albumin in heavy water. Quantitative measurements reveal excellent performance characteristics in terms of sensor linearity, wide coverage of concentrations, extending from 0.075 mg ml-1 to 92 mg ml-1 and a 55-times higher absorbance than state-of-the-art bulky and offline reference systems.
The global risk of viral disease outbreaks emphasizes the need for rapid, accurate, and sensitive detection techniques to speed up diagnostics allowing early intervention. An emerging field of microfluidics also known as the lab-on-a-chip (LOC) or micro total analysis system includes a wide range of diagnostic devices. This review briefly covers both conventional and microfluidics-based techniques for rapid viral detection. We first describe conventional detection methods such as cell culturing, immunofluorescence or enzyme-linked immunosorbent assay (ELISA), or reverse transcription polymerase chain reaction (RT-PCR). These methods often have limited speed, sensitivity, or specificity and are performed with typically bulky equipment. Here, we discuss some of the LOC technologies that can overcome these demerits, highlighting the latest advances in LOC devices for viral disease diagnosis. We also discuss the fabrication of LOC systems to produce devices for performing either individual steps or virus detection in samples with the sample to answer method. The complete system consists of sample preparation, and ELISA and RT-PCR for viral-antibody and nucleic acid detection, respectively. Finally, we formulate our opinions on these areas for the future development of LOC systems for viral diagnostics.
- Keywords
- Commercialization, Immunoassays, LOC, Microfluidic, Nucleic acid amplification, Viral detection,
- MeSH
- Biosensing Techniques MeSH
- Equipment Design MeSH
- DNA, Viral analysis MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Lab-On-A-Chip Devices * MeSH
- Humans MeSH
- Microfluidic Analytical Techniques instrumentation MeSH
- Nucleic Acids analysis MeSH
- Virus Diseases diagnosis MeSH
- Point-of-Care Systems MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Names of Substances
- DNA, Viral MeSH
- Nucleic Acids MeSH
Securing food safety standards is crucial to protect the population from health-threatening food contaminants. In the case of pesticide residues, reference procedures typically find less than 1% of tested samples being contaminated, thus indicating the necessity for new tools able to support smart and affordable prescreening. Here, we introduce a hybrid paper-lab-on-a-chip platform, which integrates on-demand injectors to perform multiple step protocols in a single disposable device. Simultaneous detection of enzymatic color response in sample and reference cells, using a regular smartphone, enabled semiquantitative detection of carbofuran, a neurotoxic and EU-banned carbamate pesticide, in a wide concentration range. The resulting evaluation procedure is generic and allows the rejection of spurious measurements based on their dynamic responses, and was effectively applied for the binary detection of carbofuran in apple extracts.
- Keywords
- 3D-printed devices, acetylcholinesterase, food safety, lab-on-a-chip, microfluidics, pesticides, screening method,
- Publication type
- Journal Article MeSH
The ever-growing field of microfluidics requires precise and flexible control over fluid flows at reduced scales. Current constraints demand a variety of controllable components to carry out several operations inside microchambers and microreactors. In this context, brand-new nanophotonic approaches can significantly enhance existing capabilities providing unique functionalities via finely tuned light-matter interactions. A concept is proposed, featuring dual on-chip functionality: boosted optically driven diffusion and nanoparticle sorting. High-index dielectric nanoantennae is specially designed to ensure strongly enhanced spin-orbit angular momentum transfer from a laser beam to the scattered field. Hence, subwavelength optical nanovortices emerge driving spiral motion of plasmonic nanoparticles via the interplay between curl-spin optical forces and radiation pressure. The nanovortex size is an order of magnitude smaller than that provided by conventional beam-based approaches. The nanoparticles mediate nanoconfined fluid motion enabling moving-part-free nanomixing inside a microchamber. Moreover, exploiting the nontrivial size dependence of the curled optical forces makes it possible to achieve precise nanoscale sorting of gold nanoparticles, demanded for on-chip separation and filtering. Altogether, a versatile platform is introduced for further miniaturization of moving-part-free, optically driven microfluidic chips for fast chemical analysis, emulsion preparation, or chemical gradient generation with light-controlled navigation of nanoparticles, viruses or biomolecules.
- Keywords
- all‐dielectric nanophotonics, lab‐on‐a‐chip platforms, nanofluidics, optomechanical manipulations, spin‐orbit couplings,
- Publication type
- Journal Article MeSH
INTRODUCTION: Nowadays, on-a-chip capillary electrophoresis is a routine method for the detection of PCR fragments. The Agilent 2100 Bioanalyzer was one of the first commercial devices in this field. Our project was designed to study the characteristics of Agilent DNA 1000 kit in PCR fragment analysis as a part of circulating tumour cell (CTC) detection technique. Despite the common use of this kit a complex analysis of the results from a long-term project is still missing. MATERIALS AND METHODS: A commercially available Agilent DNA 1000 kit was used as a final step in the CTC detection (AdnaTest) for the determination of the presence of PCR fragments generated by Multiplex PCR. Data from 30 prostate cancer patients obtained during two years of research were analyzed to determine the trueness and precision of the PCR fragment size determination. Additional experiments were performed to demonstrate the precision (repeatability, reproducibility) and robustness of PCR fragment concentration determination. RESULTS: The trueness and precision of the size determination was below 3% and 2% respectively. The repeatability of the concentration determination was below 15%. The difference in concentration determination increases when Multiplex-PCR/storage step is added between the two measurements of one sample. CONCLUSIONS: The characteristics established in our study are in concordance with the manufacturer's specifications established for a ladder as a sample. However, the concentration determination may vary depending on chip preparation, sample storage and concentration. The 15% variation of concentration determination repeatability was shown to be partly proportional and can be suppressed by proper normalization.
- Keywords
- Agilent DNA 1000 kit, capillary electrophoresis, circulating tumour cells, lab-on-a-chip devices, multiplex PCR,
- MeSH
- Actins genetics MeSH
- Antigens, Surface genetics MeSH
- DNA, Neoplasm genetics MeSH
- ErbB Receptors genetics MeSH
- Glutamate Carboxypeptidase II genetics MeSH
- Lab-On-A-Chip Devices * MeSH
- Humans MeSH
- Multiplex Polymerase Chain Reaction methods MeSH
- Biomarkers, Tumor genetics MeSH
- Neoplastic Cells, Circulating metabolism MeSH
- Prostatic Neoplasms, Castration-Resistant blood genetics MeSH
- Prostate-Specific Antigen genetics MeSH
- Reagent Kits, Diagnostic MeSH
- Gene Expression Regulation, Neoplastic * MeSH
- Reproducibility of Results MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Actins MeSH
- Antigens, Surface MeSH
- DNA, Neoplasm MeSH
- ErbB Receptors MeSH
- FOLH1 protein, human MeSH Browser
- Glutamate Carboxypeptidase II MeSH
- Biomarkers, Tumor MeSH
- Prostate-Specific Antigen MeSH
- Reagent Kits, Diagnostic MeSH
Pulsed electric field (PEF) technology is promising for the manipulation of biomolecular components and has potential applications in biomedicine and bionanotechnology. Microtubules, nanoscopic tubular structures self-assembled from protein tubulin, serve as important components in basic cellular processes as well as in engineered biomolecular nanosystems. Recent studies in cell-based models have demonstrated that PEF affects the cytoskeleton, including microtubules. However, the direct effects of PEF on microtubules are not clear. In this work, we developed a lab-on-a-chip platform integrated with a total internal reflection fluorescence microscope system to elucidate the PEF effects on a microtubules network mimicking the cell-like density of microtubules. The designed platform enables the delivery of short (microsecond-scale), high-field-strength ([Formula: see text] 25 kV/cm) electric pulses far from the electrode/electrolyte interface. We showed that microsecond PEF is capable of overcoming the non-covalent microtubule bonding force to the substrate and translocating the microtubules. This microsecond PEF effect combined with macromolecular crowding led to aggregation of microtubules. Our results expand the toolbox of bioelectronics technologies and electromagnetic tools for the manipulation of biomolecular nanoscopic systems and contribute to the understanding of microsecond PEF effects on a microtubule cytoskeleton.
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Acute intoxication incidents due to neurotoxic organophosphate (OP) insecticides are occasionally reported, related either to suicidal attempts or occupational exposure due to the misuse of protective equipment. Among them, chlorpyrifos is a compound related to great controversy, which is still authorized and easily accessible in many countries around the world. However, to screen for its exposure markers, instrumental methods are commonly applied, which cannot enable rapid monitoring at an early stage of an intoxication. Therefore, in this study, a microfluidic paper-based analytical device (μPAD) able to rapidly screen for chlorpyrifos-oxon, the toxic chlorpyrifos metabolite, in human serum was developed and fully validated. The μPAD combines wax-printed butyrylcholinesterase (BChE) paper sensors, a lab-on-a-chip (LOC) prototype injector and a smartphone as the analytical detector. In principle, the wax-printed strips with adsorbed BChE are embedded into LOC injectors able to deliver samples and reagents on-demand. A smartphone reader was used to monitor the color development on the strips providing binary qualitative results. μPAD method performance characteristics were thoroughly evaluated in terms of specificity, detection capability (CCβ) and ruggedness. The developed analytical platform is rapid (results within 10 min), cost-efficient (0.70 €), potentially applicable at the point-of-need and attained a low CCβ (10 μg L-1 in human serum). Finally, μPAD characteristics were critically compared to well-established methods, namely an in-house BChE microplate assay and liquid chromatography tandem mass spectrometry.
- Keywords
- Chlorpyrifos, Chlorpyrifos-oxon, Lab-on-a-chip, Microfluidic paper-based analytical device, Smartphone readout, Wax-printing,
- MeSH
- Smartphone MeSH
- Chlorpyrifos * MeSH
- Lab-On-A-Chip Devices MeSH
- Humans MeSH
- Microfluidics MeSH
- Microfluidic Analytical Techniques * MeSH
- Paper MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Chlorpyrifos * MeSH
Two-dimensional (2D) layered transition-metal dichalcogenides (TMDs) have been placed in the spotlight for their advantageous properties for catalytic and sensing applications. However, little work is done to explore and exploit them in enhancing the performance of analytical lab-on-a-chip (LOC) devices. In this work, we demonstrate a simple, sensitive, and low-cost fabrication of electrochemical LOC microfluidic devices to be used for enzymatic detection. We integrated four t-BuLi exfoliated, group 6 TMD materials (MoS2, MoSe2, WS2, and WSe2) within the LOC devices by the drop-casting method and compared their performance for H2O2 detection. The 1T-phase WS2-based LOC device outperformed the rest of the TMD materials and exhibited a wide range of linear response (20 nM to 20 μM and 100 μM to 2 mM), low detection limit (2.0 nM), and good selectivity for applications in real sample analysis. This work may facilitate the expanded use of electrochemical LOC microfluidics, with its easier integrability, for applications in the field of biodiagnostics and sensing.
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The development of integrated, fast and affordable platforms for pathogen detection is an emerging area where a multidisciplinary approach is necessary for designing microsystems employing miniaturized devices; these new technologies promise a significant advancement of the current state of analytical testing leading to improved healthcare. In this work, the development of a lab-on-chip microsystem platform for the genetic analysis of Salmonella in milk samples is presented. The heart of the platform is an acoustic detection biochip, integrated with a microfluidic module. This detection platform is combined with a micro-processor, which, alongside with magnetic beads technology and a DNA micro-amplification module, are responsible for performing sample pre-treatment, bacteria lysis, nucleic acid purification and amplification. Automated, multiscale manipulation of fluids in complex microchannel networks is combined with novel sensing principles developed by some of the partners. This system is expected to have a significant impact in food-pathogen detection by providing for the first time an integrated detection test for Salmonella screening in a very short time. Finally, thanks to the low cost and compact technologies involved, the proposed set-up is expected to provide a competitive analytical platform for direct application in field settings.
- MeSH
- DNA, Bacterial analysis MeSH
- Lab-On-A-Chip Devices microbiology MeSH
- Milk microbiology MeSH
- Food Microbiology methods MeSH
- Salmonella genetics isolation & purification MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- DNA, Bacterial MeSH
Proteomics provides an understanding of biological systems by enabling the detailed study of protein expression profiles, which is crucial for early disease diagnosis. Microfluidic-based proteomics enhances this field by integrating complex proteome analysis into compact and efficient systems. This review focuses on developing microfluidic chip structures for proteomics, covering on-chip sample pretreatment, protein extraction, purification, and identification in recent years. Furthermore, our work aims to inspire researchers to select proper methodologies in designing novel, efficient assays for proteomics applications by analyzing trends and innovations in this field.
- Keywords
- Lab-on-chip, Microfluidics, Proteomics,
- MeSH
- Biosensing Techniques * instrumentation MeSH
- Equipment Design MeSH
- Lab-On-A-Chip Devices * MeSH
- Humans MeSH
- Microfluidics * instrumentation methods MeSH
- Microfluidic Analytical Techniques * instrumentation methods MeSH
- Proteins isolation & purification MeSH
- Proteome * analysis isolation & purification MeSH
- Proteomics * instrumentation methods MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Names of Substances
- Proteins MeSH
- Proteome * MeSH
