A magnetoelastic biosensor based on E2 glycoprotein for wireless detection of classical swine fever virus E2 antibody

Batteryless wireless magnetostrictive Fe30Co70/Ni clad plate for human coronavirus 229E detection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been garnered increasing for its rapid worldwide spread. Each country had implemented city-wide lockdowns and immigration regulations to prevent the spread of the infection, resulting in severe economic consequences. Materials and technologies that monitor environmental conditions and wirelessly communicate such information to people are thus gaining considerable attention as a countermeasure. This study investigated the dynamic characteristics of batteryless magnetostrictive alloys for energy harvesting to detect human coronavirus 229E (HCoV-229E). Light and thin magnetostrictive Fe-Co/Ni clad plate with rectification, direct current (DC) voltage storage capacitor, and wireless information transmission circuits were developed for this purpose. The power consumption was reduced by improving the energy storage circuit, and the magnetostrictive clad plate under bending vibration stored a DC voltage of 1.9 V and wirelessly transmitted a signal to a personal computer once every 5 min and 10 s under bias magnetic fields of 0 and 10 mT, respectively. Then, on the clad plate surface, a novel CD13 biorecognition layer was immobilized using a self-assembled monolayer of -COOH groups, thus forming an amide bond with -NH₂ groups for the detection of HCoV-229E. A bending vibration test demonstrated the resonance frequency changes because of HCoV-229E binding. The fluorescence signal demonstrated that HCoV-229E could be successfully detected. Thus, because HCoV-229E changed the dynamic characteristics of this plate, the CD13-modified magnetostrictive clad plate could detect HCoV-229E from the interval of wireless communication time. Therefore, a monitoring system that transmits/detects the presence of human coronavirus without batteries will be realized soon.

Real-Time Monitoring of Breath Biomarkers with A Magnetoelastic Contactless Gas Sensor: A Proof of Concept

In the quest for effective gas sensors for breath analysis, magnetoelastic resonance-based gas sensors (MEGSs) are remarkable candidates. Thanks to their intrinsic contactless operation, they can be used as non-invasive and portable devices. However, traditional monitoring techniques are bound to slow detection, which hinders their application to fast bio-related reactions. Here we present a method for real-time monitoring of the resonance frequency, with a proof of concept for real-time monitoring of gaseous biomarkers based on resonance frequency. This method was validated with a MEGS based on a Metglass 2826 MB microribbon with a polyvinylpyrrolidone (PVP) nanofiber electrospun functionalization. The device provided a low-noise (RMS = 1.7 Hz), fast (<2 min), and highly reproducible response to humidity (Δf = 46−182 Hz for 17−95% RH), ammonia (Δf = 112 Hz for 40 ppm), and acetone (Δf = 44 Hz for 40 ppm). These analytes are highly important in biomedical applications, particularly ammonia and acetone, which are biomarkers related to diseases such as diabetes. Furthermore, the capability of distinguishing between breath and regular air was demonstrated with real breath measurements. The sensor also exhibited strong resistance to benzene, a common gaseous interferent in breath analysis.

Laser-Fabricated 2D Molybdenum Disulfide Electronic Sensor Arrays for Rapid, Low-Cost, Ultrasensitive Detection of Influenza A and SARS-Cov-2

Multiplex electronic antigen sensors for detection of SARS-Cov-2 spike glycoproteins and hemagglutinin from influenza A are fabricated using scalable processes for straightforward transition to economical mass-production. The sensors utilize the sensitivity and surface chemistry of a 2D MoS₂ transducer for attachment of antibody fragments in a conformation favorable for antigen binding with no need for additional linker molecules. To make the devices, ultra-thin layers (3 nm) of amorphous MoS₂ are sputtered over pre-patterned metal electrical contacts on a glass chip at room temperature. The amorphous MoS₂ is then laser annealed to create an array of semiconducting 2H-MoS₂ transducer regions between metal contacts. The semiconducting crystalline MoS₂ region is functionalized with monoclonal antibody fragments complementary to either SARS-CoV-2 S1 spike protein or influenza A hemagglutinin. Quartz crystal microbalance experiments indicate strong binding and maintenance of antigen avidity for antibody fragments bound to MoS₂. Electrical resistance measurements of sensors exposed to antigen concentrations ranging from 2-20 000 pg mL^-1 reveal selective responses. Sensor architecture is adjusted to produce an array of sensors on a single chip suited for detection of analyte concentrations spanning six orders of magnitude from pg mL^-1 to µg mL^-1.

Magnetoelastic Resonance Sensors: Principles, Applications, and Perspectives

Magnetoelastic resonators are gaining attention as an incredibly versatile and sensitive transduction platform for the detection of varied physical, chemical, and biological parameters. These sensors, based on the coupling effect between mechanical and magnetic properties of ME platforms, stand out in comparison to alternative technologies due to their low cost and wireless detection capability. Several parameters have been optimized over the years to improve their performance, such as their composition, surface functionalization, or shape geometry. In this review, the working principles, recent advances, and future perspectives of magnetoelastic resonance transducers are introduced, highlighting their potentials as a versatile platform for sensing applications. First, the fundamental principles governing the magnetoelastic resonators performance are introduced as well as the most common magnetoelastic materials and their main fabrication methods are described. Second, the versatility and technical feasibility of magnetoelastic resonators for biological, chemical, and physical sensing are highlighted and the most recent results and functionalization processes are summarized. Finally, the forefront advances to further improve the performance of magnetoelastic resonators for sensing applications have been identified.

Magnetoelastic Immunosensor via Antibody Immobilization for the Specific Detection of Lysozymes

Lysozymes in human urine have crucial clinical significance as an indicator of renal tubular and glomerular diseases. Most lysozyme detection methods rely on the enzyme-linked immunosorbent assay (ELISA), which is usually a tedious procedure. Meanwhile, aptamer sensors and fluorescence-based techniques for lysozyme detection have emerged in recent studies. However, these methods are time-consuming and highly complex in operation, and some even require exorbitant reagents and instruments, which restricts real-time clinical monitoring as diagnostic approaches. Therefore, a rapid and low-cost lysozyme detection method with facile preparation is still in demand for modern precision medicine. Herein, we propose a magnetoelastic (ME) immunosensor for lysozyme detection by detecting changes in resonance frequency under a magnetostrictive effect. The detection system is composed of a magnetoelastic chip with an immobilized lysozyme antibody, a solenoid coil, and a vector network analyzer. Since the ME sensor is ultrasensitive to mass change, the frequency offset caused by mass change can be utilized to detect the content of lysozyme. The immunosensor is evaluated to possess superior sensitivity of 138 Hz/μg mL^-1 in terms of the resonance frequency shift (RFS). In addition, our sensor displays an outstanding performance in specificity experiments and shows a relatively lower detection limit (1.26 ng/mL) than other conventional lysozyme detection methods (such as ELISA, chemiluminescence assay, fluorescence, and aptamer biosensors).

On the Possibility of Developing Magnetostrictive Fe-Co/Ni Clad Plate with Both Vibration Energy Harvesting and Mass Sensing Elements

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) has spread rapidly around the world. In order to prevent the spread of infection, city blockades and immigration restrictions have been introduced in each country, but these measures have a severe serious impact on the economy. This paper examines the possibility of both harvesting vibration energy and detecting mass by using a magnetostrictive alloy. Few efforts have been made to develop new magnetostrictive biosensor materials. Therefore, we propose magnetostrictive Fe-Co/Ni clad steel vibration energy harvesters with mass detection, and we numerically and experimentally discuss the effect of the proof mass weight on the frequency shift and output voltage induced by bending vibration. The results reveal that the frequency and output voltage decrease significantly as the mass increases, indicating that the energy harvesting device is capable of mass detection. In the future, device miniaturization and the possibility of virus detection will be considered.

Recent Advances in Nanotechnology-Based Biosensors Development for Detection of Arsenic, Lead, Mercury, and Cadmium

Heavy metals cause considerable environmental pollution due to their extent and non-degradability in the environment. Analysis and trace levels of arsenic, lead, mercury, and cadmium as the most toxic heavy metals show that they can cause various hazards in humans' health. To achieve rapid, high-sensitivity methods for analyzing ultra-trace amounts of heavy metals in different environmental and biological samples, novel biosensors have been designed with the participation of strategies applied in nanotechnology. This review attempted to investigate the novel, sensitive, efficient, cost-benefit, point of care, and user-friendly biosensors designed to detect these heavy metals based on functional mechanisms. The study's search strategies included examining the primary databases from 2015 onwards and various keywords focusing on heavy metal biosensors' performance and toxicity mechanisms. The use of aptamers and whole cells as two important bio-functional nanomaterials is remarkable in heavy metal diagnostic biosensors' bioreceptor design. The application of hybridized nanomaterials containing a specific physicochemical function in the presence of a suitable transducer can improve the sensing performance to achieve an integrated detection system. Our study showed that in addition to both labeled and label-free detection strategies, a wide range of nanoparticles and nanocomposites were used to modify the biosensor surface platform in the detection of heavy metals. The detection limit and linear dynamic range as an essential characteristic of superior biosensors for the primary toxic metals are studied. Furthermore, the perspectives and challenges facing the design of heavy metal biosensors are outlined. The development of novel biosensors and the application of nanotechnology, especially in real samples, face challenges such as the capability to simultaneously detect multiple heavy metals, the interference process in complex matrices, the efficiency and stability of nanomaterials implemented in various laboratory conditions.

A Review of Piezoelectric and Magnetostrictive Biosensor Materials for Detection of COVID-19 and Other Viruses

The spread of the severe acute respiratory syndrome coronavirus has changed the lives of people around the world with a huge impact on economies and societies. The development of wearable sensors that can continuously monitor the environment for viruses may become an important research area. Here, the state of the art of research on biosensor materials for virus detection is reviewed. A general description of the principles for virus detection is included, along with a critique of the experimental work dedicated to various virus sensors, and a summary of their detection limitations. The piezoelectric sensors used for the detection of human papilloma, vaccinia, dengue, Ebola, influenza A, human immunodeficiency, and hepatitis B viruses are examined in the first section; then the second part deals with magnetostrictive sensors for the detection of bacterial spores, proteins, and classical swine fever. In addition, progress related to early detection of COVID-19 (coronavirus disease 2019) is discussed in the final section, where remaining challenges in the field are also identified. It is believed that this review will guide material researchers in their future work of developing smart biosensors, which can further improve detection sensitivity in monitoring currently known and future virus threats.

A chemiluminescence immunoassay for rapid detection of classical swine fever virus E2 antibodies in pig serum samples

The high performance of chemiluminescence immunoassays (CLIAs) in diagnosis has been gradually recognized in recent years, but their application in the diagnosis of classical swine fever (CSF) has not been reported. Here, a recombinant E2 (rE2) protein and a peroxidase-conjugated monoclonal antibody (MAb G5) were used to develop a competition-based chemiluminescence immunoassay (cCLIA) for rapid and accurate detection of E2-specific antibodies in pig serum. To evaluate the feasibility of cCLIA in the diagnosis of CSF, we developed a competition-based enzyme-linked immunosorbent assay (cELISA) as a control. Under the optimum test conditions, cCLIA showed a higher signal-to-noise ratio than that of the control cELISA. The best signal-to-noise ratios of cCLIA and cELISA were 70 and 17, respectively. Then, the diagnostic performance of the two assays was compared by examining a panel of pig serum samples (n = 285) with a confirmed status, and cCLIA showed higher diagnostic sensitivity (Dn) and diagnostic specificity (Dp) values than those of cELISA. The Dn and Dp of cCLIA were 97.49% and 96.08%, respectively, and those of cELISA were 93.97% and 94.12%, respectively. Furthermore, cCLIA can provide results within 20 min, whereas the control cELISA requires at least 1 hr. According to these findings, the newly developed cCLIA has potential application in the diagnosis of CSF and offers an alternative approach for efficient and rapid detection of E2-specific antibodies.