Diagnostic Biosensors Research Articles

Materdicine: Interdiscipline of materials and medicine

AbstractThe clinical medicine and biomaterials are two fields that are conducive to achieve the goal of precise medicine on diagnostics and therapeutics of various diseases. The interdiscipline of materials and medicine, termed/abbreviated as “materdicine,” seeks to address the dominant medical shortcomings and challenges faced by conventional medicine, including inferior bioavailability, systemic toxicity, poor targeting specificity, and unsatisfied diagnostic/therapeutic efficacy. In this review, we present the perspective and discussion on the use of diverse biomaterials for disease diagnosis and treatment from a broad perspective, especially on nanoscale biomaterials. We initially highlight the recent advances on the engineering of abundant contrast agents for diagnostic bioimaging, such as optical fluorescence imaging, magnetic resonance imaging, and photoacoustic imaging. In addition, discussions on the diagnostic biosensing for point‐of‐care diagnosis, such as fluorescent and plasmonic sensors, are supplemented. Furthermore, we outline several materdicine‐enabled therapeutic modalities for disease treatments, including the following exemplified scaffold biomaterials for regenerative medicine. Especially, rational modulation of toxicity issues of micro‐/nanoscale biomaterials is also accounted for addressing the possible concerns of biocompatibility and biosafety on further clinical translation of materdicine. Finally, we summarize facing challenges and outlook future developments relating to the clinical translation of these distinctive biomaterials in materdicine.

Graphene oxide-based molecular diagnostic biosensor for simultaneous detection of Zika and dengue viruses

The world’s tropical and sub-tropical regions are at risk for Zika and dengue virus (ZIKV, DENV) spread. Co-infection between ZIKV and DENV and repeated DENV infections of different serotypes increase the disease severity by impairing immune responses. Therefore, to avoid high risks of virus infection and achieve effective clinical management, development of diagnostic sensor for rapid and accurate identification of each virus is very important. Herein, we report a graphene oxide-based multiplexed detection strategy to make the differential diagnosis of Zika and dengue viruses by targeting virus nucleic acid. The fluorometric detection strategy is integrated with loop-mediated isothermal amplification assay to further increase sensitivity. In the presence of target virus, fluorescent PNA probes recognize the single-stranded loops of the cauliflower-like-shaped virus amplicon in a sequence-specific manner. Meanwhile, graphene oxide functions to distinguish the valid fluorescence signal as a selective fluorescence quencher for single-stranded PNA probes. The present strategy allows multiplexed detection of closely related viruses for specific discrimination of the virus nucleic acids with simplified molecular diagnostic steps, without requiring any nucleic acid isolation step.

Polyethylene glycol-mediated blocking and monolayer morphology of an electrochemical aptasensor for malaria biomarker detection in human serum

Better approaches are critically needed for in situ point-of-care diagnostic biosensors that enable primary care physicians, or even individual patients, to directly analyze biological fluids without complicated sample pretreatments. Additional purification steps consume time, consume reagents, often require other equipment, and can introduce false-negative results. Biosensors have been modified with blocking molecules to reduce biofouling; however, the effectiveness relies on their chemical composition and morphology. Here, we used a polyethylene glycol film to suppress unspecific binding from human serum on an electrochemical malaria aptasensor. A detailed study of the variation of the chemical and morphological composition of the aptamer/polyethylene glycol mixed monolayer as a function of incubation time was conducted. Higher resistance to matrix biofouling was found for polyethylene glycol than for hydrophobic alkanethiol films. The best sensor performance was observed for intermediate polyethylene glycol immobilization times. With prolonged incubation, phase separation of aptamer, and polyethylene glycol molecules locally increased the aptamer density and thereby diminished the analyte binding capability. Remarkably, polyethylene glycols do not affect the aptasensor sensitivity but enhance the complex matrix tolerance, the dynamic range, and the limit of detection. Careful tuning of the blocking molecule immobilization is crucial to achieving high aptasensor performance and biofouling resistance.

Protein based biomarkers for non-invasive Covid-19 detection

COVID-19 has become a substantial lethal disease worldwide, and early diagnosis is a significant concern for this virus. Currently, RT-PCR is being used worldwide for the detection of this virus with human to human transmission. Furthermore, the recent develop biosensor leading to others diagnosis approach but being invasive are painful and time taking. Another possibility can be protein-based biomarkers as an application of biosensors for detection and early diagnostics. Considering the other approach, that is, microfluidics-based biosensor, though being a non-invasive method, will be restricting virus transmission. This review commences with the recent develop biosensor for Covid-19 detection and listing down the available biomarkers with their secretion range comparison of normal to COVID-19 patients through clinical analysis in china and concludes with the future approach for the diagnosis.

Diagnostic methods and potential portable biosensors for coronavirus disease 2019

Timely detection and diagnosis are urgently needed to guide epidemiological measures, infection control, antiviral treatment, and vaccine research. In this review, biomarkers/indicators for diagnosis of coronavirus disease 2019 (COVID-19) or detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the environment are summarized and discussed. It is concluded that the detection methods targeting antibodies are not suitable for screening of early and asymptomatic cases since most patients had an antibody response at about 10 days after onset of symptoms. However, antibody detection methods can be combined with quantitative real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) to significantly improve the sensitivity and specificity of diagnosis, and boost vaccine research. Fast, sensitive and accurate detection methods targeting antigens need to be developed urgently. Various specimens for diagnosis or detection are compared and analyzed. Among them, deep throat saliva and induced sputum are desired for RT-qPCR test or other early detection technologies. Chest computerized tomography (CT) scan, RT-qPCR, lateral flow immunochromatographic strip (LFICS) for diagnosis of COVID-19 are summarized and compared. Specially, potential electrochemical (EC) biosensor, surface enhanced Raman scattering (SERS)-based biosensor, field-effect transistor (FET)-based biosensor, surface plasmon resonance (SPR)-based biosensor and artificial intelligence (AI) assisted diagnosis of COVID-19 are emphasized. Finally, some commercialized portable detection device, current challenges and future directions are discussed.

Glycopolymer Brushes by Reversible Deactivation Radical Polymerization: Preparation, Applications, and Future Challenges.

The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell–cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical polymerization (RDRP) methods allows the development of tailor-made materials with high affinity for lectins because of their multivalent interaction. These polymers are promising candidates for the biomedical field, namely as novel diagnostic disease markers, biosensors, or carriers for tumor-targeted therapy. Although linear glycopolymers are extensively studied for lectin recognition, branched glycopolymeric structures, such as polymer brushes can establish stronger interactions with lectins. This specific glycopolymer topology can be synthesized in a bottlebrush form or grafted to/from surfaces by using RDRP methods, allowing a precise control over molecular weight, grafting density, and brush thickness. Here, the preparation and application of glycopolymer brushes is critically discussed and future research directions on this topic are suggested.

Oxygen Vacancy-Enhanced Electrochemiluminescence Sensing Strategy Using Luminol Thermally Encapsulated in Apoferritin as a Transducer for Biomarker Immunoassay.

Oxygen vacancies (OVs) enhanced electrochemiluminescence (ECL) biosensing strategy using luminol thermally encapsulated in apoferritin (Lum@apoFt) as an efficient transducer was investigated for ultrasensitive biomarker detection. By applying the oxygen-defect engineering (ODE) strategy, the OVs enriched cobalt-iron oxide (r-CoFe2O4) was fabricated as the sensing substrate to boost the electron mobility and catalyze the generation of superoxide anion radical (O2•-) for signal amplification. It should be noted that r-CoFe2O4 with higher OVs density dramatically accelerated the ECL reaction between O2•- and luminol anionic radicals, achieving 6.5-fold stronger ECL output than CoFe2O4 with no or low OVs density. Moreover, facile encapsulation of approximate 412 luminol molecules in a single apoFt cavity was first realized by an efficient thermal-induction method. The obtained Lum@apoFt complexes exhibited well-maintained ECL efficiency and excellent biocompatibility for biological modifications. On this basis, a biosensor was developed for early diagnostics of squamous cell carcinomas by detecting its representative biomarker named cytokeratin 19 fragment 21-1 (CYFRA 21-1), from which excellent linearity was achieved in 0.5 pg/mL to 50 ng/mL with a detection limit of 0.14 pg/mL. This work not only put forward a novel idea of creating OVs enriched sensing interface with excellent signal-amplification function but also proposes a facile and robust methodology to design apoFt-based transducers for developing more practical nanoscale biosensors in early diagnostics of diseases.

Wien Oscillator Using Organic Enzyme‐Chemiresistors for Fused Measurement of Glucose and Lactate

Total body sensor networks for physiological (diagnostic biosensors) and biomechanical (force and motion) systems require data fusion through several algorithms. A novel, device‐level method of sensor data fusion is presented. This biomimetic concept is demonstrated through the development of glucose and lactate sensitive chemiresistors in a biologically responsive Wien bridge oscillator circuit. Biocompatible and bioresponsive polymers suitable for integration of molecular recognition and transduction yield stimuli‐responsive chemiresistors. The analyte‐responsive chemiresistors are electroconductive hydrogels that separately incorporate the enzymes glucose oxidase and/or lactate oxidase that are conjugated with single‐walled carbon nanotubes (SWCNTs) and embedded in a percolating network of conductive polymer (polypyrrole). The input of the system is the chemical potential of the analytes, glucose and lactate, acting through the biological activity of immobilized enzymes, and the output of the system is a single sinusoidal wave from which the concentrations of glucose and lactate can be deconvoluted from the amplitude and DC offset, respectively. This engineered system, based on soft bioelectronic circuit elements, aims to offer simultaneous, real‐time analyte biosensing at a biomolecular level in a move toward biologically responsive circuits and eventually, bioanalytical systems suitable for indwelling in human tissue for extended periods of time.

(Invited) Passive Eccrine Sweat Analysis Technologies; A New Paradigm in Sweat Analytics

Wearable electronic monitors hold great promise in helping people to reach their health goals. These increasingly sophisticated devices help the wearers improve their wellness by constantly monitoring their activities and bodily responses. While consumer wearables that are non–sweat based have been useful for monitoring body vital parameters. However, solutions leveraging human sweat are still in the early stages of development. Wearable devices hold the potential to transform some industries most importantly the health care industry.Wearable sweat based diagnostic biosensors for the detection and monitoring of analytes in transdermal sweat present an intriguing pathway toward improving user health outcomes in an inexpensive and noninvasive manner. Transdermal biosensors have become a more viable option in recent years, due in large part to the miniaturization of conventional sensing mechanisms. Current minimally invasive strategies demonstrate encouraging results in the monitoring of select biomarkers in peripheral blood and interstitial fluid, but these devices are still minimally invasive as they puncture the skin. Current transdermal sweat biosensors require relatively large volumes in a localized region and count on chemically-induced sweating to attain sufficient sample volume. Thus, there exists a challenge in designing wearable sweat-based sensors that can report and quantify biomarkers of interest from low volumes of human sweat in a completely non-invasive yet still cost-effective manner. In this talk I will present some non-invasive sweat sensing technologies that detect and quantify biomarkers in human sweat.

Current progresses and trends in carbon nanomaterials‐based electrochemical and electrochemiluminescence biosensors

AbstarctThe enormous potential of biosensors in medical diagnostics has motivated scientists to develop newer innovative tools and advance biosensing technologies. The use of cell, organelles, nucleotides, aptamers, antibodies, affibodies, proteins, peptides, molecules, and printed polymers, merged with nanotechnology, offers excellent tools to prepare highly sensitive and advanced biosensors. Therefore, the current decade has witnessed a rapid surge in the fabrication of different nanomaterial‐based biosensors. Among them, carbon nanomaterials (CNMs) have emerged highly attractive in the fabrication of both electrochemical and electrochemiluminescence (ECL) biosensors. On one hand, CNMs bear prominent electrical conductivity, large surface area to immobilize adequate amount of biomolecules, an enhanced loading capacity, improved biocompatibility, and active site for electrochemical reaction. Additionally, CNMs could be chemically modified for the covalent coupling with the biomolecules. On the other hand, both electrochemical and ECL biosensors allow for cost‐effective, rapid, and real‐time detection with excellent sensitivity and selectivity, with the capability of integrating different biomolecules and CNMs on the same chip. However, currently there is not a single review, which includes CNM‐based electrochemical and ECL biosensors' current progress and trends. Therefore, this review intends to survey the current progress and future trends in CNM‐based electrochemical and ECL biosensors.

Purification of animal immunoglobulin G (IgG) using peptoid affinity ligands.

The availability of highly pure animal antibodies is critical in the production of diagnostic tools and biosensors. The peptoid PL16, previously isolated from an ensemble of peptoid variants of the IgG-binding peptide HWRGWV, was utilized in this work as affinity ligand on WorkBeads resin for the purification of immunoglobulin G (IgG) from a variety of mammalian sources and chicken immunoglobulin Y (IgY). The chromatographic protocol initially optimized for murine serum and ascites was subsequently employed for processing rabbit, goat and sheep, donkey, llama, and chicken sera. The PL16-WorkBeads resin proved able to recover all antibody targets with values of yield between 50 and 90%, and purity consistently above 90%. Notably, PL16 not only binds a broader spectrum of animal immunoglobulins than the reference ligands Protein A and G, but it also binds equally well with all their subclasses. Unlike the protein ligands, in fact, PL16 afforded excellent values of yield and purity of mammalian polyclonal IgG, namely murine (47 and 94%), rabbit (66.5 and 91.7%), caprine IgG (63 and 91-95%), donkey, and llama (93 and 97%), as well as chicken IgY (42 and 92%). Of notice, it is also the ability of PL16 to target monomeric IgG without binding aggregated IgG; when challenged with a mixture of monomeric and aggregated murine IgG, PL16 eluted <3% of fed aggregates, against 11-13% eluted by Protein A and G. Collectively, these results prove the potential of the proposed peptoid ligand for large-scale purification of animal immunoglobulins.

Robust Single-Molecule Enzyme Nanocapsules for Biosensing with Significantly Improved Biosensor Stability.

The present study demonstrates the use of highly stable single-molecule enzyme nanocapsules (SMENs) instead of traditional native enzyme as biorecognition element in enzyme-based biosensors. The main purpose of this study is to resolve the major obstacle and challenge in the biosensor field, i.e., the poor stability of enzyme-based biosensors, including thermal stability, organic solvent tolerance, long-term operational stability, etc. Highly active and robust SMENs of glucose oxidase (GOx, as a model enzyme) were synthesized (nGOx) using an in situ polymerization strategy in an aqueous environment. The particle-size distribution, transmission electron microscopic (TEM) images, and UV-vis spectral characterization revealed the formation of a thin polymer layer around each enzyme molecule. The polymer shell effectively stabilized the GOx enzyme core while enabling rapid substrate transportation, resulting in a new class of biocatalytic nanocapsules. Multiple covalent attachments between a thin polymer layer and an enzyme molecule strengthened the encapsulated GOx molecule. Encapsulation created a favorable microenvironment to avoid any structural dissociation at high temperature and helped to retain essential water during the organic solvent operation. The present work reports a study implementing nGOx SMENs as highly stable nano(bio)sensors for point-of-care diagnostic applications. Prepared nGOx SMENs manifested significantly improved thermal stability (even at 65 °C) and organic solvent tolerance without any compromise in biocatalytic activity. For example, the native GOx-based biosensor lost its catalytic activity for glucose after 4 h of incubation at high temperature (65 °C), while the nGOx/N-CNTs-Chi/GCE nano(bio)sensor maintained ∼56% of its original catalytic activity for glucose oxidation. The proposed SMENs-based nano(bio)sensors with robust stability in variable working environment could promote the development and applications of biosensors in point-of care diagnostics, biomedical detection, wearable devices, implantable equipment, and biofuel cells.

Magnetic Particles: Their Applications from Sample Preparations to Biosensing Platforms.

The growing interest in magnetic materials as a universal tool has been shown by an increasing number of scientific publications regarding magnetic materials and its various applications. Substantial progress has been recently made on the synthesis of magnetic iron oxide particles in terms of size, chemical composition, and surface chemistry. In addition, surface layers of polymers, silica, biomolecules, etc., on magnetic particles, can be modified to obtain affinity to target molecules. The developed magnetic iron oxide particles have been significantly utilized for diagnostic applications, such as sample preparations and biosensing platforms, leading to the selectivity and sensitivity against target molecules and the ease of use in the sensing systems. For the process of sample preparations, the magnetic particles do assist in target isolation from biological environments, having non-specific molecules and undesired molecules. Moreover, the magnetic particles can be easily applied for various methods of biosensing devices, such as optical, electrochemical, and magnetic phenomena-based methods, and also any methods combined with microfluidic systems. Here we review the utilization of magnetic materials in the isolation/preconcentration of various molecules and cells, and their use in various techniques for diagnostic biosensors that may greatly contribute to future innovation in point-of-care and high-throughput automation systems.

Label-Free Biosensors for Laboratory-Based Diagnostics of Infections: Current Achievements and New Trends.

Infections pose a serious global public health problem and are a major cause of premature mortality worldwide. One of the most challenging objectives faced by modern medicine is timely and accurate laboratory-based diagnostics of infectious diseases. Being a key factor of timely initiation and success of treatment, it may potentially provide reduction in incidence of a disease, as well as prevent outbreak and spread of dangerous epidemics. The traditional methods of laboratory-based diagnostics of infectious diseases are quite time- and labor-consuming, require expensive equipment and qualified personnel, which restricts their use in case of limited resources. Over the past six decades, diagnostic technologies based on lateral flow immunoassay (LFIA) have been and remain true alternatives to modern laboratory analyzers and have been successfully used to quickly detect molecular ligands in biosubstrates to diagnose many infectious diseases and septic conditions. These devices are considered as simplified formats of modern biosensors. Recent advances in the development of label-free biosensor technologies have made them promising diagnostic tools that combine rapid pathogen indication, simplicity, user-friendliness, operational efficiency, accuracy, and cost effectiveness, with a trend towards creation of portable platforms. These qualities exceed the generally accepted standards of microbiological and immunological diagnostics and open up a broad range of applications of these analytical systems in clinical practice immediately at the site of medical care (point-of-care concept, POC). A great variety of modern nanoarchitectonics of biosensors are based on the use of a broad range of analytical and constructive strategies and identification of various regulatory and functional molecular markers associated with infectious bacterial pathogens. Resolution of the existing biosensing issues will provide rapid development of diagnostic biotechnologies.

The application of antibody-aptamer hybrid biosensors in clinical diagnostics and environmental analysis.

The growing number of various diseases and the increase of environmental contamination are the causes for the development of novel methods for their detection. The possibility of the application of affinity-based biosensors for such purposes seems particularly promising as they provide high selectivity and low detection limits. Recently, the usage of hybrid antibody-aptamer sandwich constructs was shown to be more advantageous in terms of working parameters in comparison to aptamer-based and immune-based biosensors. This review is focused on the usage of hybrid antibody-aptamer receptor layers for the determination of clinically and environmentally important target molecules. In this work, antibodies and aptamer molecules are characterized and the methods of their immobilization as well as analytical signal generation are shown. This is followed by the critical presentation of examples of hybrid sandwich biosensors that have been elaborated in the past 12 years.

Nanozyme-based electrochemical biosensors for disease biomarker detection.

In recent years, a new group of nanomaterials named nanozymes that exhibit enzyme-mimicking catalytic activity has emerged as a promising alternative to natural enzymes. Nanozymes can address some of the intrinsic limitations of natural enzymes such as high cost, low stability, difficulty in storage, and specific working conditions (i.e., narrow substrate, temperature and pH ranges). Thus, synthesis and applications of hybrid and stimuli-responsive advanced nanozymes could revolutionize the current practice in life sciences and biosensor applications. On the other hand, electrochemical biosensors have long been used as an efficient way for quantitative detection of analytes (biomarkers) of interest. As such, the use of nanozymes in electrochemical biosensors is particularly important to achieve low cost and stable biosensors for prognostics, diagnostics, and therapeutic monitoring of diseases. Herein, we summarize the recent advances in the synthesis and classification of common nanozymes and their application in electrochemical biosensor development. After briefly overviewing the applications of nanozymes in non-electrochemical-based biomolecular sensing systems, we thoroughly discuss the state-of-the-art advances in nanozyme-based electrochemical biosensors, including genosensors, immunosensors, cytosensors and aptasensors. The applications of nanozymes in microfluidic-based assays are also discussed separately. We also highlight the challenges of nanozyme-based electrochemical biosensors and provide some possible strategies to address these limitations. Finally, future perspectives on the development of nanozyme-based electrochemical biosensors for disease biomarker detection are presented. We envisage that standardization of nanozymes and their fabrication process may bring a paradigm shift in biomolecular sensing by fabricating highly specific, multi-enzyme mimicking nanozymes for highly sensitive, selective, and low-biofouling electrochemical biosensors.

Competition-Based Universal Photonic Crystal Biosensors by Using Antibody-Antigen Interaction.

Sensors capable of detecting different types of biomolecules have widespread applications in the field of biomedical research, but despite many years of research, the development of biosensors suitable for point-of-care (POC) applications in resource-limited areas is still extremely challenging. Sensors based on photonic crystal hydrogels (PCHs) hold much promise in this regard because of their numerous advantages over other existing bioanalytical methods. All current PCH biosensors are however restricted in the types of analytes they can detect sensitively with good selectivity. By taking advantage of the powerful and ubiquitous antibody-antigen interaction, we report herein the first-ever competition-based PCH biosensors capable of naked-eye detection of various biomolecules (e.g., proteins, peptides, and small molecules) with high sensitivity and selectivity and minimal background and excellent reversibility. We showed such PCH designs could be extended to the fabrication of different enzyme-detecting biosensors. The universal feature of these novel biosensors thus enables future development of POC biosensors in disease diagnostics for other bioanalytes.

The role of nanotechnology for improving crop production

Today, green nanotechnology has great importance due to the presence of different modes of restrictive action against various pathogens such as fungi and bacterial species. The use of nanomaterials has recently increased in agriculture and plant-tissue culture thanks to their unique different properties such as; magnetic, electrical, mechanical, optical, and chemical properties. Optimum use of iron increases protein content in the wheat grain. They also enhance plant growth by improving disease resistance and increase stability of the plants by anti-bending and deeper rooting of crops. It has been reported by many researchers that Nano-fertilizers significantly influenced the seed germination which demonstrated the effect of Nano fertilizers on seed and seed vigor. Chemical methods have been used for the synthesis of nanoparticles. Developing Nano-biotechnology is generating interests in research towards eco-friendly, cost effective and biological synthesis of nanoparticles. Nanoparticles systems have been combined into plant fungal disease controlpractices. Using nanoparticles as biosensors in plant disease diagnostics is also illustrated.

Design and analysis of microfluidic cell counter using spice simulation

Microfluidic cytometers based on Coulter principle have recently shown a great potential for point of care biosensors for medical diagnostics. In this study, the design and characterization of Coulter-based microfluidic cytometer are investigated through electrical circuit simulations considering an equivalent electrical model for the biological cell. We explore the effects related to microelectrode dimensions, microfluidic detection volume, suspension medium, size/morphology of the target cells, and the impedance of the external readout circuit, on the output response of the sensor. We show that the effect of microelectrodes’ surface area and the dielectric properties of the suspension medium should be carefully considered when characterizing the output response of the sensor. In particular, the area of the microelectrodes can have a significant effect on cell’s electrical opacity (the ratio of cell impedance at high to low frequency) which is commonly used to distinguish between subpopulations of the target cells (e.g., lymphocytes vs. monocytes when counting white blood cells). Moreover, we highlight that the opacity response versus frequency can significantly vary based upon whether the absolute cell impedance or the differential output impedance is used in its calculation. These insights could provide valuable guidelines for the design and characterization of Coulter-based microfluidic sensors.

Highly sensitive immunodiagnostics at the point of care employing alternative recognition elements and smartphones: hype, trend, or revolution?

Immunodiagnostic tests performed at the point of care (POC) today usually employ antibodies for biorecognition and are read out either visually or with specialized equipment. Availability of alternative biorecognition elements with promising features as well as smartphone-based approaches for signal readout, however, challenge the described established configuration in terms of analytical performance and practicability. Assessing these developments' clinical relevance and their impact on POC immunodiagnostics is demanding. The first part of this review will therefore give an overview on suitable diagnostic biosensors based on alternative recognition elements (such as nucleic acid-based aptamers or engineered binding proteins) and exemplify advantages and drawbacks of these biomolecules on the base of selected assays. The second part of the review then focuses on smartphone-connected diagnostics and discusses the indispensable considerations required for successful future clinical POCT implementation. Together, the joint depiction of two of the most innovative and exciting developments in the field will enable the reader to cast a glance into the distant future of POC immunodiagnostics.