Micropump integrated white blood cell separation platform for detection of chronic granulomatous disease

White blood cells (WBCs) are robust defenders during antigenic challenges and prime immune cell functioning indicators. High-purity WBC separation is vital for various clinical assays and disease diagnosis. Red blood cells (RBCs) are a major hindrance in WBC separation, constituting 1000 times the WBC population. The study showcases a low-cost micropump integrated microfluidic platform to provide highly purified WBCs for point-of-care testing. An integrated user-friendly microfluidic platform was designed to separate WBCs from finger-prick blood (⁓5 μL), employing an inertial focusing technique. We achieved an efficient WBC separation with 86% WBC purity and 99.99% RBC removal rate in less than 1 min. In addition, the microdevice allows lab-on-chip colorimetric evaluation of chronic granulomatous disease (CGD), a rare genetic disorder affecting globally. The assay duration, straight from separation to disease detection, requires only 20 min. Hence, the proposed microfluidic platform can further be implemented to streamline various clinical procedures involving WBCs in healthcare industries.

In a century from agitated cells to human organoids

Reaching back more than a century, suspension cultures have provided major insights into processes of histogenesis; e.g., cell communication, distinction of self/nonself, cell sorting and cell adhesion. Besides studies on lower animals, the vertebrate retina served as excellent reaggregate model to analyze 3D reconstruction of a complex neural laminar tissue. Methodologically, keeping cells under suspension is essential to achieve tissue organisation in vitro; thereby, the environmental conditions direct the emergent histotypic particulars. Recent progress in regenerative medicine is based to a large extent on human induced pluripotent stem cells (hiPSCs), which are cultured under suspension. Following their genetically directed differentiation into various histologic 3D structures, organoids provide excellent multipurpose in vitro assay models, as well as tissues for repair transplantations. Historically, a nearly fully laminated retinal spheroid from avian embryos was achieved already in 1984, foreshadowing the potential of culturing stem cells under suspension for tissue reconstruction purposes.

Current progress in high-throughput screening for drug repurposing

High-throughput screening (HTS) is a simple, rapid and cost-effective solution to determine active candidates from large library of compounds. HTS is gaining attention from Pharmaceuticals and Biotechnology companies for accelerating their drug discovery programs. Conventional drug discovery program is time consuming and expensive. In contrast drug repurposing approach is cost-effective and increases speed of drug discovery as toxicity profile is already known. The present chapter highlight HTS technology including microplate, microfluidics, lab-on-chip, organ-on-chip for drug repurposing. The current chapter also highlights the application of HTS for bacterial infections and cancer.

Prospectives and retrospectives of microfluidics devices and lab-on-A-chip emphasis on cancer

Microfluidics is a science and technology that deals with the concept of "less sample-to-more precision" enabling portable device development via fabrication for in vitro analysis. On evolution, microfluidic system lead to the development of Organ-on-chip where recapitulation of organ's functionality and pathophysiological response can be performed under controlled environment. Further microfluidic-based "Lab-on-chip" device, a versatile innovation credited for its number of parameters that has capability to leverage next-generation companion of medicines. This emulsion science has enormous practise in the field of regenerative medicine, drug screening, medical diagnosis and therapy for accuracy in results. In this era of personalized medicine, getting precise tools for applying these theranostics is crucial. Oncological theranostics create a new gateway to develop precision in personalized medicine for cancer, where microfluidic chips are involved in diagnosis and therapy of various cancers using biomarkers for thyroid, lung cancers, and assay based for breast, circulating tumor cells and colorectal cancers and nanoparticles for ovarian cancer. This review shows more comprehensive approach to the state of art with respect to microfluidic devices in cancer theranostics.

Recent advances in aptamer-based platforms for cortisol hormone monitoring

The stressful conditions of today-life make it urgent the timely prevention and treatment of many physiological and psychological disorders related to stress. According to the significant progress made in the near future, rapid, accurate, and on-spot measurement of cortisol hormone as a dominant stress biomarker using miniaturized digital devices is not far from expected. With a special potency in the fields of diagnosis and healthcare monitoring, aptamer-mediated biosensors (aptasensors) are promising for the quantitative monitoring of cortisol levels in the different matrices (sweat, saliva, urine, cerebrospinal fluid, blood serum, etc.). Accordingly, this in-depth study reviews the superior achievements in the aptasensing strategies to detect cortisol hormone with the synergism of diverse two/three dimensional nanostructured materials, enzymatic amplification components, and antibody motifs. The represented discussions offer a universal perspective to achieve lab-on-chip aptasensing arrays as future user-friendly skin-patchable electronic gadgets for on-site and real-time quantification of cortisol levels.

Lab-on-chip technologies for space research - current trends and prospects

The in-depth analysis concerning application of microfluidic instruments for space biology research is presented. The article focuses on recently investigated key scientific fields, i.e., lab-on-chips applied to the biomedical studies performed in the (1) International Space Station and (2) CubeSat nanosatellites. The paper presents also the lab-on-chip devices that were fabricated with a view to future space biology research and to those that to date have been solely been tested under Earth laboratory conditions and/or simulated microgravity environments. NASA and ESA conceptual mission plans for future are also mentioned, concerning for instance "tissue chips" and the ESA-SPHEROIDS campaign. The paper ends with final conclusions and future perspectives regarding lab-on-chip application in the space biology sector and its impact on novel biomedical and pharmaceutical strategies.

A portable automated chip for simultaneous rapid point-of-care testing of multiple β-agonists

Abusive use of β-agonists as feed additives for animals and medication is detrimental to human health and food safety. Conventional assays are restricted to a single type of β-agonists detection and cannot match the multiplexing features to perform automated, high throughput, and rapid quantitative analysis in real samples. In this research, we develop a portable automated chip system (PACS) with highly integrated automated devices in conjunction with portable microfluidic chips to provide simultaneous point-of-care testing of multiple β-agonists in the field, simplifying complex manual methods, shortening assay times, and improving sensitivity. Specifically, silicon film is used as reaction substrates for immobilizing the conjugates of β-agonists to increase the sensitivity of the assay result. Then, the PACS with a chemiluminescence imaging detector is established for automatic high-throughput and sensitive detection of Clenbuterol, Ractopamine, and Salbutamol based on the indirect immunoassay. Newly developed chip with high mixing performance can improve the sensitivity of target determination. Multiplex assays were carried out using the developed system for Clenbuterol, Ractopamine, and Salbutamol with a limit of detection of 54 pg mL-1,59 pg mL-1, and 93 pg mL-1, respectively. Except for sample preparation and coating, the detection in the PACS takes less than 47 min. A satisfactory sample recovery (86.33%-108.12%) was obtained, validating the reliability and practical applicability of this PACS. Meanwhile, the PACS enables sensitive and rapid detection of multiple β-agonists in farms or markets where lacking advanced laboratory facilities.

3D bio-printed hydrogel inks promoting lung cancer cell growth in a lab-on-chip culturing platform

The results of a lab-on-chip (LOC) platform fabrication equipped with a hydrogel matrix is reported. A 3D printing technique was used to provide a hybrid, "sandwiched" type structure, including two microfluidic substrates of different origins. Special attention was paid to achieving uniformly bio-printed microfluidic hydrogel layers of a unique composition. Six different hydrogel inks were proposed containing sodium alginate, agar, chitosan, gelatin, methylcellulose, deionized water, or 0.9% NaCl, varying in proportions. All of them exhibited appropriate mechanical properties showing, e.g., the value of elasticity modulus as similar to that of biological tissues, such as skin. Utilizing our biocompatible, entirely 3D bio-printed structure, for the first time, a multi-drug-resistant lung cancer cell line (H69AR) was cultured on-chip. Biological validation of the device was performed qualitatively and quantitatively utilizing LIVE/DEAD assays and Presto blue staining. Although all bio-inks exhibited acceptable cell viability, the best results were obtained for the hydrogel composition including 3% sodium alginate + 7% gelatin + 90% NaCl (0.9%), reaching approximately 127.2% after 24 h and 105.4% after 48 h compared to the control group (100%). Further research in this area will focus on the microfluidic culture of the chosen cancer cell line (H69AR) and the development of novel drug delivery strategies towards appropriate in vivo models for chemotherapy and polychemotherapy treatment.

Classification of nucleic acid amplification on ISFET arrays using spectrogram-based neural networks

The COVID-19 pandemic has highlighted a significant research gap in the field of molecular diagnostics. This has brought forth the need for AI-based edge solutions that can provide quick diagnostic results whilst maintaining data privacy, security and high standards of sensitivity and specificity. This paper presents a novel proof-of-concept method to detect nucleic acid amplification using ISFET sensors and deep learning. This enables the detection of DNA and RNA on a low-cost and portable lab-on-chip platform for identifying infectious diseases and cancer biomarkers. We show that by using spectrograms to transform the signal to the time-frequency domain, image processing techniques can be applied to achieve the reliable classification of the detected chemical signals. Transformation to spectrograms is beneficial as it makes the data compatible with 2D convolutional neural networks and helps gain significant performance improvement over neural networks trained on the time domain data. The trained network achieves an accuracy of 84% with a size of 30kB making it suitable for deployment on edge devices. This facilitates a new wave of intelligent lab-on-chip platforms that combine microfluidics, CMOS-based chemical sensing arrays and AI-based edge solutions for more intelligent and rapid molecular diagnostics.

Molecular imprinting-based sensors: Lab-on-chip integration and biomedical applications

The innovative technology of a marketable lab-on-a-chip platform for point-of-care (POC) in vitro detection has recently attracted remarkable attention. The POC tests can significantly enhance the high standard of medicinal care. In the last decade, clinical diagnostic technology has been broadly advanced and successfully performed in several areas. It seems that lab-on-a-chip approaches play a significant role in these technologies. However, high-cost and time-consuming methods are increasing the challenge and the development of a cost-effective, rapid and efficient method for the detection of biomolecules is urgently needed. Recently, polymer-coated sensing platforms have been a promising area that can be employed in medical diagnosis, pharmaceutical bioassays, and environmental monitoring. The designed on-chip sensors are based on molecular imprinting polymers (MIPs) that use label-free detection technology. Molecular imprinting shines out as a potentially promising technique for creating artificial recognition material with molecular recognition sites. MIPs provide unique advantages such as excellent recognition specificity, high selectivity, and good reusability. This review article aims to define several methods using molecular imprinting for biomolecules and their incorporation with several lab-on-chip technologies to describe the most promising methods for the development of sensing systems based on molecularly imprinted polymers. The higher selectivity, more user-friendly operation is believed to provide MIP-based lab-on-a-chip devices with great potential academic and commercial value in on-site clinical diagnostics and other point-of-care assays.

Discrimination of bacterial and viral infection using host-RNA signatures integrated in a lab-on-chip platform

The unmet clinical need for accurate point-of-care (POC) diagnostic tests able to discriminate bacterial from viral infection demands a solution that can be used both within healthcare settings and in the field, and that can also stem the tide of antimicrobial resistance. Our approach to solve this problem combine the use of host gene signatures with our Lab-on-a-Chip (LoC) technology enabling low-cost POC expression analysis to detect Infectious Disease. Transcriptomics have been extensively investigated as a potential tool to be implemented in the diagnosis of infectious disease. On the other hand, LoC technologies using ion-sensitive field-effect transistor (ISFET), in conjunction with isothermal chemistries, are offering a promising alternative to conventional amplification instruments, owing to their portable and affordable nature. Currently, the data analysis of ISFET arrays are restricted to established methods by averaging the output of every sensor to give a single time-series. This simple approach makes unrealistic assumptions, leading to insufficient performance for applications that require accurate quantification such as Host-Transcriptomics. In order to reliably quantify transcripts on our LoC platform enabling the classification of infectious disease on-chip, we propose a novel data-driven algorithm for extracting time-to-positive values from ISFET arrays. The algorithm proposed correctly outputs a time-to-positive for all the reactions, with a high correlation to RT-qLAMP (0.85, R2 = 0.98, p < 0.01), resulting in a classification accuracy of 100% (CI, 95-100%). This work aims to bridge the gap between translating assays from microarray analysis to ISFET arrays providing benefits on tackling infectious disease and diagnostic testing in hard-to-reach areas of the world.

Metal organic frameworks as advanced functional materials for aptasensor design

BACKGROUND

Advancement in coordination chemistry has achieved an impressive development of metal organic frameworks (MOFs) as the supramolecular hybrid materials, comprising harmonized metal nodes with organic ligands. Scope and approach: MOFs offer the unique properties of easy synthesis, nanoscale structure, adjustable size and morphology, high porosity, large surface area, supreme chemical tunability and stability, and biocompatibility. The features provide an exceptional opportunity for the widely usage of MOFs in the different scientific fields, e.g. biomedicine, electrocatalysis, food safety, energy storage, environmental surveillance, and biosensing platforms. The synergistic incorporation of the aptamer advantages and the superiorities of MOFs attains the novel MOF-based aptasensors. The excellent selectivity and sensitivity of the MOF-based aptasensors nominate them as efficient lab-on-chip tools for cost-effective, label-free, portable, and real-time monitoring of diverse targets.

KEY FINDINGS AND CONCLUSIONS

Here, we review the achievements in the sensor design by cooperation of MOF motifs and aptamers with the conspicuous potential of determining the targets. Finally, some results are expressed that provide a valuable viewpoint for developing the novel MOF-based test strips in the future.

Microfluidics based point-of-care for disease diagnostics

Microfluidics platform is widely used for several basic biological to advanced biotechnological applications. It reduces the expenditure of reagent consumption by readily reducing the volume of the reaction system. It is being used for early diagnosis of diseases, detection of pathogens, cancer markers, high-throughput screening and many such applications. Currently, microfluidics and lab-on-chip is integrated together with sample preparation, extraction, analysis and detection of biomarkers for disease diagnosis. This technology offers low-cost, rapid, sensitive and paper-based lateral flow mode of detection which is user-friendly and scalable. In this chapter, we highlight recent developments in microfluidics platform for disease diagnosis.

Current progress in aptamer-based sensing tools for ultra-low level monitoring of Alzheimer's disease biomarkers

Alzheimer's disease (AD) as common late-life dementia is pathologically associated with the irreversible and progressive disorder, misfolding, deposition, and accumulation of the brain proteins. Especially, the formation of fibrous amyloid plaques by aggregation of amyloid-β peptides is the pathological cause of this neurologic disorder disease. Besides, tau protein isoforms destabilize the microtubule filaments through post-translational modifications and induce nerve cells' death. Amyloid-β peptides and tau proteins are considered as the critical symptom and reliable molecular biomarkers for the early diagnosis of AD. AD is characterized by impaired thinking proficiencies, cognitive decline, memory loss, and behavioral disability. Since there is no efficacious therapy for AD at present, the development of precise sensing tools for the early diagnosis of this disease is essential and crucial. Aptamer-based biosensors (aptasensors) have acquired utmost importance in the field of AD healthcare, due to excellent sensitivity and specificity, ease-of-use, cost-effectiveness, portability, and rapid assay time. Here, we highlight the recent developments and novel perspectives in the field of aptasensor design to quantitatively monitor the AD biomarkers. Finally, some results are represented to achieve a promising viewpoint for introducing the novel aptasensor test kits in the future.

Comprehensive review of conventional and state-of-the-art detection methods of Cryptosporidium

Cryptosporidium is a critical waterborne protozoan pathogen found in water resources that have been a major cause of death and serious illnesses worldwide, costing millions of dollars annually for its detection and treatment. Over the past several decades, substantial efforts have been made towards developing techniques for the detection of Cryptosporidium. Early diagnostic techniques were established based on the existing tools in laboratories, such as microscopes. Advancements in fluorescence microscopy, immunological, and molecular techniques have led to the development of several kits for the detection of Cryptosporidium spp. However, these methods have several limitations, such as long processing times, large sample volumes, the requirement for bulky and expensive laboratory tools, and the high cost of reagents. There is an urgent need to improve these existing techniques and develop low-cost, portable and rapid detection tools for applications in the water quality industry. In this review, we compare recent advances in nanotechnology, biosensing and microfluidics that have facilitated the development of sophisticated tools for the detection of Cryptosporidium spp.Finally, we highlight the advantages and disadvantages, of these state-of-the-art detection methods compared to current analytical methodologies and discuss the need for future developments to improve such methods for detecting Cryptosporidium in the water supply chain to enable real-time and on-site monitoring in water resources and remote areas.

Droplet Magnetofluidic Assay Platform for Quantitative Methylation-Specific PCR

Early cancer detection requires identification of cellular changes resulting from oncogenesis. Abnormal DNA methylation patterns occurring early in tumor development have been widely identified as early biomarkers for multiple types of cancer tumors. Methylation-Specific PCR (MSP) has permitted highly sensitive detection of these methylation changes at known biomarker locations. MSP requires multiple sample preparation steps including protein digestion, DNA isolation, and bisulfite conversion prior to detection. In this work, we present a streamlined assay platform and instrumentation for integration of all sample processing steps required to obtain quantitative MSP signal from raw biological samples through the use of droplet magnetofluidic principles. In conjunction with this platform, we present a streamlined protocol for solid-phase DNA extraction from cells and bisulfite conversion of genomic DNA, minimizing the processing steps and reagent volume for implementation on a compact assay platform.

Cell Death Analysis in Cancer Spheroids from a Microfluidic Device

Microfluidic technology facilitates the generation of 3D spheroids from cancer cells, a more suitable model for preclinical therapeutic studies. This system opens the possibility to test many drugs combination at a low cost. Here we describe the use of microfluidic devices for cytotoxicity evaluation on cancer spheroids for the discovery of drugs that could be used in combination with radiotherapy. Device fabrication, preparation, and seeding are also covered. Cell death arising following treatment is detected and characterized according to spheroid size, colony formation assays, and flow cytometry analysis of apoptotic marker annexin V.

A novel liquid crystal-based aptasensor for ultra-low detection of ochratoxin a using a π-shaped DNA structure: Promising for future on-site detection test strips

Ochratoxin A (OTA) as the most dangerous mycotoxin is produced by Aspergillus Ochraceus and Penicillium verrucosum. OTA can be found in beverages and foodstuffs that induces the teratogenic, nephrotoxic, carcinogenic, and immunosuppressive effects on humans. Hence, developing highly sensitive methods for its detection is of great importance. Herein, a novel aptasensor was designed for the label-free monitoring of the ultra-low OTA levels by a combination of the superiority of aptamers and long-range orientational order of liquid crystals (LCs). The aptasensing strategy was based on the conformational switch of the immobilized π-shaped DNA structure on the glass substrate in presence of the target. A shift in the orientation of LCs from random to homeotropic state led to the apparent alteration of the optical appearance of the aptasensor platform from bright to dark. The LC-based aptasensor especially detects OTA at the ultra-trace level as low as 0.63 aM with comparable selectivity. The aptasensor could detect OTA successfully in the grape juice, coffee, and human serum samples. The LC-based aptasensor paves a way for developing portable and real-time sensing probes with high performance for food safety control and clinical application.

Manipulation of self-assembled three-dimensional architecture in reusable acoustofluidic device

Reconstructing of cell architecture plays a vital role in tissue engineering. Recent developments of self-assembling of cells into three-dimensional (3D) matrix pattern using surface acoustic waves have paved a way for a better tissue engineering platform thanks to its unique properties such as nature of noninvasive and noncontact, high biocompatibility, low-power consumption, automation capability, and fast actuation. This article discloses a method to manipulate the orientation and curvature of 3D matrix pattern by redesigning the top wall of microfluidic chamber and the technique to create a 3D longitudinal pattern along preinserted polydimethylsiloxane (PDMS) rods. Experimental results showed a good agreement with model predictions. This research can actively contribute to the development of better organs-on-chips platforms with capability of controlling cell architecture and density. Meanwhile, the 3D longitudinal pattern is suitable for self-assembling of microvasculatures.

Utility of low-cost, miniaturized peristaltic and Venturi pumps in droplet microfluidics

Many laboratory applications utilizing droplet microfluidics rely on precision syringe pumps for flow generation. In this study, the use of an open-source peristaltic pump primarily composed of 3D printed parts and a low-cost commercial Venturi pump are explored for their use as an alternative to syringe pumps for droplet microfluidics. Both devices provided stable flow (<2% RSD) over a range of 1-7 μL/min and high reproducibility in signal intensity at a droplet generation rate around 0.25 Hz (<3% RSD), which are comparable in performance to similar measurements on standard syringe pumps. As a novel flow generation source for microfluidic applications, the use of the miniaturized Venturi pump was also applied to droplet signal monitoring studies used to measure changes in concentration over time, with average signal reproducibility <4% RSD for both single-stream fluorometric and reagent addition colorimetric applications. These low-cost flow methods provide stable flow sufficient for common droplet microfluidic approaches and can be implemented in a wide variety of simple, and potentially portable, analytical measurement devices.

A microfluidic platform for dissociating clinical scale tissue samples into single cells

The advancement of sample preparation techniques is essential for the field of cell-based therapeutics. To obtain cells suited for clinical applications, the entire process starting from acquiring donor tissue biopsy, all through cell transplantation into the recipient, should occur in an integrated, safe, and efficient system. The current laboratory approach for solid tissue-to-cell isolation is invasive and involves multiple incoherent manual procedures running in an open operator-dependent system. Such an approach provides a chain of events for systematic cell loss that would be unfavorable for rare cell populations such as adult and cancer stem cells. A few lab-on-chip platforms were proposed to process biological tissues, however, they were limited to partial tissue dissociation and required additional processing off-chip. Here, we report the first microfluidic platform that can dissociate native biological tissue into ready-to-use single cells. The platform can merge the successive steps of tissue dissociation, debris filtration, cell sieving, washing, and staining in one streamlined process. Performance of the platform was tested with diverse biological tissues and it could yield viable cells that were ready for on or off-chip cell culture without further processing. Microfluidic tissue dissociation using this platform produced a higher number of viable single cells (an average of 2262 cells/ml per milligram of tissue compared to 1233.25 cells/ml/mg with conventional dissociation).

Glial-fibrillary-acidic-protein (GFAP) biomarker detection in serum-matrix: Functionalization strategies and detection by an ultra-high-frequency surface-acoustic-wave (UHF-SAW) lab-on-chip

Glial-fibrillary-acidic-protein (GFAP) has recently drawn significant attention from the clinical environment as a promising biomarker. The pathologies which can be linked to the presence of GFAP in blood severely affect the human central nervous system. These pathologies are glioblastoma multiforme (GBM), traumatic brain injuries (TBIs), multiple sclerosis (MS), intracerebral hemorrhage (ICH), and neuromyelitis optica (NMO). Here, we develop three different detection strategies for GFAP, among the most popular in the biosensing field and never examined side by side within the experimental frame. We compare their capability of detecting GFAP in a clean-buffer and serum-matrix by using gold-coated quartz-crystal-microbalance (QCM) sensors. All the three detection strategies are based on antibodies, and each of them focuses on a key aspect of the biosensing process. The first is based on a polyethylene glycol (PEG) chain for antifouling, the second on a protein-G linker for controlling antibody-orientation, and the third on antibody-splitting and direct surface immobilization for high-surface coverage. Then, we select the best-performing protocol and validate its detection performance with an ultra-high-frequency (UHF) surface-acoustic-wave (SAW) based lab-on-chip (LoC). GFAP successful detection is demonstrated in a clean-buffer and serum-matrix at a concentration of 35 pM. This GFAP level is compatible with clinical diagnostics. This result suggests the use of our technology for the realization of a point-of-care biosensing platform for the detection of multiple brain-pathology biomarkers.

Scalable COVID-19 Detection Enabled by Lab-on-Chip Biosensors

Introduction

The emergence of a novel coronavirus, SARS-CoV-2, has highlighted the need for rapid, accurate, and point-of-care diagnostic testing. As of now, there is not enough testing capacity in the world to meet the stated testing targets, which are expected to skyrocket globally for broader testing during reopening

Aim

This review focuses on the development of lab-on-chip biosensing platforms for diagnosis of COVID-19 infection.

Results

We discuss advantages of utilizing lab-on-chip technologies in response to the current global pandemic, including their potential for low-cost, rapid sample-to-answer processing times, and ease of integration into a range of healthcare settings. We then highlight the development of magnetic, colorimetric, plasmonic, electrical, and lateral flow-based lab-on-chip technologies for the detection of SARS-CoV-2, in addition to other viruses. We focus on rapid, point-of-care technologies that can be deployed at scale, as such devices could be promising alternatives to the current gold standard of reverse transcription-polymerase chain reaction (RT-PCR) diagnostic testing.

Conclusion

This review is intended to provide an overview of the current state-of-the-field and serve as a resource for innovative development of new lab-on-chip assays for COVID-19 detection.

Towards pharmacological treatment screening of cardiomyocyte cells using Si nanowire FETs

Silicon nanowires (Si NWs) are the most promising candidates for recording biological signals due to improved interfacing properties with cells and the possibility of high-speed transduction of biochemical signals into detectable electrical responses. The recording of extracellular action potentials (APs) from cardiac cells is important for fundamental studies of AP propagation features reflecting cell activity and the influence of pharmacological substances on the signal. We applied a novel approach of using fabricated Si NW field-effect transistors (FETs) in combination with fluorescent marker techniques to evaluate the functional activity of cardiac cells. Extracellular AP signal recording from HL-1 cardiomyocytes was demonstrated. This method was supplemented by studies of the pharmacological effects of stimulations using noradrenaline (NorA) as a modulator of functional activity on a cellular and subcellular levels, which were also tested using fluorescent marker techniques. The role of calcium alteration and membrane potential were revealed using Fluo-4 AM and tetramethylrhodamine, methyl ester, perchlorate (TMRM) fluorescent dyes. In addition, chemical treatment with sodium dodecyl sulfate (SDS) solutions was tested. The results obtained demonstrate positive prospects for AP monitoring in different treatments for studies related to a wide range of myocardial diseases using lab-on-chip technology.

Genotyping Citrus tristeza virus Isolates by Sequential Multiplex RT-PCR and Microarray Hybridization in a Lab-on-Chip Device

Citrus tristeza virus (CTV) is the largest known plant RNA virus (ca. 20 Kb), with a plethora of isolates conventionally categorized into six main genotypic groups (T36, VT, T3, RB, T68, T30). Each group includes many isolates with different phenotype profiles. Several techniques and protocols, mostly based on RT-PCR analysis of different regions of specific genes, have been developed for managing the diseases caused by CTV. However, more accurate genomic information would help to plan a correct strategy. This chapter describes a pilot protocol based on a sequential multiplex RT-PCR reaction and microarray hybridization in a miniaturized silicon lab-on-chip (LoC) device. The system comprises a set of 12 primers and 44 probes (× 2 replicates), designed on variable genomic regions of 6 genes: 5'UTR, ORF1a, ORF1b (RdRp), p33, p20, and p23. The system can rapidly analyze any genotype diversity associated with field isolates and distinguish the endemic from the non-endemic isolates. The identification of CTV strains is based on a number of probe hybridizations, which varies according to the genotypes present in the isolates and the differences among the genotypes.

Microfluidic electrochemical immunosensor for the trace analysis of cocaine in water and body fluids

Quick but accurate testing and on-the-spot monitoring of cocaine in oral fluids and urine continues to be an important toxicological issue. In terms of drug testing, a number of devices have been introduced into the market in recent decades, notably for workplace inspection or roadside testing. However, these systems do not always fulfill the requirements in terms of reliability, especially when low cut-off levels are required. With respect to surface water, the presence of anthropogenic small organic molecules such as prescription and over-the-counter pharmaceuticals as well as illicit drugs like cannabinoids, heroin, or cocaine, has become a challenge for scientists to develop new analytical tools for screening and on-site analysis because many of them serve as markers for anthropogenic input and consumer behavior. Here, a modular approach for the detection of cocaine is presented, integrating an electrochemical enzyme-linked immunosorbent assay (ELISA) performed on antibody-grafted magnetic beads in a hybrid microfluidic sensor utilizing flexible tubing, static chip and screen-printed electrode (SPE) elements for incubation, recognition, and cyclic voltammetry measurements. A linear response of the sensor vs. the logarithm of cocaine concentration was obtained with a limit of detection of 0.15 ng/L. Within an overall assay time of 25 minutes, concentrations down to 1 ng/L could be reliably determined in water, oral fluids, and urine, the system possessing a dynamic working range up to 1 mg/L.

Bisintercalating DNA redox reporters for real-time electrochemical qLAMP

The electrochemical detection methods have emerged as a potential alternative to the bench-top optical systems in monitoring nucleic acid amplification. DNA intercalating redox reporters play a crucial role in such monitoring schemes. Here, a series of bisintercalating redox probes have been tailor-made to meet specific requirements of electrochemical quantitative loop-mediated isothermal amplification (qLAMP). The probes composed of two naphthoquinone-imidazole (NQIM) derivatives as signal motifs that are covalently bridged by different linkers (R). They are bis-NQIM-R; R = Alkane (Ak), ethylene glycol (EG) and phenyl (Ph). The linkers allow the probes to be fine-tuned for securing ideal redox reporter. DNA binding studies via electrochemical and fluorescence techniques demonstrate that the bis-NQIM-R probes possess better ds-DNA bisintercalating ability compared to their mono-analogs. The bis-NQIM-Ph was implemented in a real-time electrochemical qLAMP, for which a prototype custom-made device that can perform fully automated multiplexed analyses is devised. A single copy of Salmonella DNA was quantified in just 10 min and the performance is comparable to the benchtop fluorescence method. Thus, the bisintercalating redox reporters incorporated electrochemical detection schemes hold great promise in qLAMP.

A sample-to-answer droplet magnetofluidic assay platform for quantitative methylation-specific PCR

Dysregulation of DNA methylation has been identified as an epigenetic biomarker for numerous cancer types. Gene-specific identification techniques relying on methylation-specific PCR (MSP) require a lengthy manual benchtop process that is susceptible to human-error and contamination. This MSP assay requires a series of discrete sample processing steps including genomic DNA extraction, bisulfite conversion and readout via PCR. In this work, we present a streamlined assay platform utilizing droplet magnetofluidic principles for integration of all sample processing steps required to obtain quantitative MSP signal from raw biological samples. We present a streamlined protocol for solid-phase extraction and bisulfite conversion of genomic DNA, which minimizes reagent use and simplifies the sample preparation protocol for implementation on a compact assay platform. Furthermore, we present a thermally robust assay chip that enables DNA extraction, bisulfite conversion and quantitative PCR from biological samples on a single device. Technical improvements to facilitate DNA extraction and PCR on a single chip in addition to chip performance characterization data are presented.

On-a-chip Biosensing Based on All-Dielectric Nanoresonators

Nanophotonics has become a key enabling technology in biomedicine with great promises in early diagnosis and less invasive therapies. In this context, the unique capability of plasmonic noble metal nanoparticles to concentrate light on the nanometer scale has widely contributed to biosensing and enhanced spectroscopy. Recently, high-refractive index dielectric nanostructures featuring low loss resonances have been proposed as a promising alternative to nanoplasmonics, potentially offering better sensing performances along with full compatibility with the microelectronics industry. In this letter we report the first demonstration of biosensing with silicon nanoresonators integrated in state-of-the-art microfluidics. Our lab-on-a-chip platform enables detecting Prostate Specific Antigen (PSA) cancer marker in human serum with a sensitivity that meets clinical needs. These performances are directly compared with its plasmonic counterpart based on gold nanorods. Our work opens new opportunities in the development of future point-of-care devices toward a more personalized healthcare.

Advances in developing rapid, reliable and portable detection systems for alcohol

Development of portable, reliable, sensitive, simple, and inexpensive detection system for alcohol has been an instinctive demand not only in traditional brewing, pharmaceutical, food and clinical industries but also in rapidly growing alcohol based fuel industries. Highly sensitive, selective, and reliable alcohol detections are currently amenable typically through the sophisticated instrument based analyses confined mostly to the state-of-art analytical laboratory facilities. With the growing demand of rapid and reliable alcohol detection systems, an all-round attempt has been made over the past decade encompassing various disciplines from basic and engineering sciences. Of late, the research for developing small-scale portable alcohol detection system has been accelerated with the advent of emerging miniaturization techniques, advanced materials and sensing platforms such as lab-on-chip, lab-on-CD, lab-on-paper etc. With these new inter-disciplinary approaches along with the support from the parallel knowledge growth on rapid detection systems being pursued for various targets, the progress on translating the proof-of-concepts to commercially viable and environment friendly portable alcohol detection systems is gaining pace. Here, we summarize the progress made over the years on the alcohol detection systems, with a focus on recent advancement towards developing portable, simple and efficient alcohol sensors.

Nanotechnology for Food Packaging and Food Quality Assessment

Nanotechnology has paved the way to innovative food packaging materials and analytical methods to provide the consumers with healthier food and to reduce the ecological footprint of the whole food chain. Combining antimicrobial and antifouling properties, thermal and mechanical protection, oxygen and moisture barrier, as well as to verify the actual quality of food, e.g., sensors to detect spoilage, bacterial growth, and to monitor incorrect storage conditions, or anticounterfeiting devices in food packages may extend the products shelf life and ensure higher quality of foods. Also the ecological footprint of food chain can be reduced by developing new completely recyclable and/or biodegradable packages from natural and eco-friendly resources. The contribution of nanotechnologies to these goals is reviewed in this chapter, together with a description of portable devices ("lab-on-chip," sensors, nanobalances, etc.) which can be used to assess the quality of food and an overview of regulations in force on food contact materials.

A parallelized microfluidic DNA bisulfite conversion module for streamlined methylation analysis

Aberrant methylation of DNA has been identified as an epigenetic biomarker for numerous cancer types. The vast majority of techniques aimed at detecting methylation require bisulfite conversion of the DNA sample prior to analysis, which until now has been a benchtop process. Although microfluidics has potential benefits of simplified operation, sample and reagent economy, and scalability, bisulfite conversion has yet to be implemented in this format. Here, we present a novel droplet microfluidic design that facilitates rapid bisulfite conversion by reducing the necessary processing steps while retaining comparable performance to existing methods. This new format has a reduced overall processing time and is readily scalable for use in high throughput DNA methylation analysis.

Simultaneous detection of multiple lower genital tract pathogens by an impedimetric immunochip

Lower genital tract infections caused by both sexually and not-sexually transmitted pathogens in women are a key public health priority worldwide, especially in developing countries. Since standard analyses are time-consuming, appropriate therapeutic intervention is often neglected or delayed. Lab-on-chips and biosensors open new perspectives and offer innovative tools to simplify the diagnosis by medical staff, especially in countries with inadequate resources. Here we report a biosensing platform based on Electrochemical Impedance Spectroscopy (EIS) that allows multiplexed detection of Candida albicans, Streptococcus agalactiae and Chlamydia trachomatis with a single biochip, enabling a quick screening thanks to the presence of different immobilized antibodies, each specific for one of the different target pathogens.

Polysilicon nanogap lab-on-chip facilitates multiplex analyses with single analyte

Rationally designed biosensing system supports multiplex analyses is warranted for medical diagnosis to determine the level of analyte interaction. The chemically functionalized novel multi-electrode polysilicon nanogap (PSNG) lab-on-chip is designed in this study, facilitates multiplex analyses for a single analyte. On the fabricated 69nm PSNG, biocompatibility and structural characteristics were verified for the efficient binding of Human Chorionic Gonadotropin (hCG). With the assistance of microfluidics, hCG sample was delivered via single-injection to 3-Aminopropyl(triethoxy)silane (APTES) and Glycidoxypropyl(trimethoxy)silane (GPMS) modified PSNG electrodes and the transduced signal was used to investigate the dielectric mechanisms for multiplex analyses. The results from amperometric response and impedance measurement delivered the scale of interaction between anti-hCG antibody and hCG that exhibited 6.5 times higher sensitivity for the chemical linker, APTES than GPMS. Under optimized experimental conditions, APTES and GPMS modified immunosensor has a limit of detection as 0.56mIU/ml and 2.93mIU/ml (at S/N=3), with dissociation constants (Kd) of 5.65±2.5mIU/ml and 7.28±2.6mIU/ml, respectively. These results suggest that multiplex analysis of single target could enhance the accuracy of detection and reliable for real-time comparative analyses. The designed PSNG is simple, feasible, requires low sample consumption and could be applied for any given multiplex analyses.

A portable and integrated instrument for cell manipulation by dielectrophoresis

The physical manipulation of biological cells is a key point in the development of miniaturized systems for point-of-care analyses. Dielectrophoresis (DEP) has been reported by several laboratories as a promising method in biomedical research for label-free cell manipulation without physical contact, by exploiting the dielectric properties of cells suspended in a microfluidic sample, under the action of high-gradient electric fields. In view of a more extended use of DEP phenomena in lab-on-chip devices for point-of-care settings, we have developed a portable instrument, integrating on the same device the microfluidic biochip for cell manipulation and all the laboratory functions (i.e., DEP electric signal generation, microscopic observation of the biological sample under test and image acquisition) that are normally obtained by combining different nonportable standard laboratory instruments. The nonuniform electric field for cell manipulation on the biochip is generated by microelectrodes, patterned on the silicon substrate of microfluidic channels, using standard microfabrication techniques. Numerical modeling was performed to simulate the electric field distribution, quantify the DEP force, and optimize the geometry of the microelectrodes. The developed instrument includes an electronic board, which allows the control of the electric signal applied to electrodes necessary for DEP, and a miniaturized optical microscope system that allows visual inspection and eventually cell counting, as well as image and video recording. The system also includes the control software. The portable and integrated platform described in this work therefore represents a complete and innovative solution of applied research, suitable for many biological applications.

Clinical laboratory data: acquire, analyze, communicate, liberate

The availability of portable healthcare devices, which can acquire and transmit medical data to remote experts would dramatically affect healthcare in areas with poor infrastructure. Smartphones, which feature touchscreen computer capabilities and sophisticated cameras, have become widely available with over billion units shipped in 2013. In the clinical laboratory, smartphones have recently brought the capabilities of key instruments such as spectrophotometers, fluorescence analyzers and microscopes into the palm of the hand. Several research groups have developed sensitive and low-cost smartphone-based diagnostic assay prototypes for testing cholesterol, albumin, vitamin D, tumor markers, and the detection of infectious agents. This review covers the use of smartphones to acquire, analyze, communicate, and liberate clinical laboratory data. Smartphones promise to dramatically improve the quality and quantity of healthcare offered in resource-limited areas.

How medium osmolarity influences dielectrophoretically assisted on-chip electrofusion

Cells submitted to an electric field gradient experience dielectrophoresis. Such a force is useful for pairing cells prior to electrofusion. The latter event is induced by the application of electric field pulses leading to membrane fusion while cells are in physical contact. Nevertheless, the efficiency of dielectrophoretic pairing and electrofusion of cells are highly dependent on medium properties (osmolarity and conductivity). In this paper, we examine the effect of medium osmolarity on volume, viability and electrical properties of cells. Then we characterize in real time the impact of electropermeabilization of cells on their dielectrophoretic response. To do so, a microfluidic device, inducing particular field topologies is used. These real time observations are correlated to numerical analysis of the Clausius-Mossotti factor. Taking into account the identified changes, an electrofusion protocol adequate to the optimal medium (100 mOsm, 0.03 S/m) is defined. Up to 75% simultaneous binuclear rapid electrofusions were achieved and monitored with average membrane fusion duration lower than 12s.

Ultrasound assisted particle and cell manipulation on-chip

Ultrasonic fields are able to exert forces on cells and other micron-scale particles, including microbubbles. The technology is compatible with existing lab-on-chip techniques and is complementary to many alternative manipulation approaches due to its ability to handle many cells simultaneously over extended length scales. This paper provides an overview of the physical principles underlying ultrasonic manipulation, discusses the biological effects relevant to its use with cells, and describes emerging applications that are of interest in the field of drug development and delivery on-chip.