Cold-hot Janus electrochemical aptamer-based sensor for calibration-free determination of biomolecules.

Real-time, high-frequency measurements of pharmaceuticals, metabolites, exogenous antigens, and other biomolecules in biological samples can provide critical information for health management and clinical diagnosis. Electrochemical aptamer-based (EAB) sensor is a promising analytical technique capable of achieving these goals. However, the issues of insufficient sensitivity, frequent calibration and lack of adapted portable electrochemical device limit its practical application in immediate detection. In response we have fabricated an on-chip-integrated, cold-hot Janus EAB (J-EAB) sensor based on the thermoelectric coolers (TECs). Attributed to the Peltier effect, the enhanced/suppressed current response can be generated simultaneously on cold/hot sides of the J-EAB sensor. The ratio of the current responses on the cold and hot sides was used as the detection signal, enabling rapid on-site, calibration-free determination of small molecules (procaine) as well as macromolecules (SARS-CoV-2 spike protein) in single step, with detection limits of 1 µM and 10 nM, respectively. We have further demonstrated that the J-EAB sensor is effective in improving the ease and usability of the actual detection process, and is expected to provide a universal, low-cost, fast and easy potential analytical tool for other clinically important biomarkers, drugs or pharmaceutical small molecules.

Functionalized N95 Face Mask with a Chemical-Free Paper-Based Collector for Exhaled Breath Analysis: SARS-CoV-2 Detection with a Printed Immunosensor as a Case Study.

Exhaled breath electrochemical sensing is a promising biomedical technology owing to its portability, painlessness, cost-effectiveness, and user-friendliness. Here, we present a novel approach for target analysis in exhaled breath by integrating a comfortable paper-based collector into an N95 face mask, providing a universal solution for analyzing several biomarkers. As a model analyte, we detected SARS-CoV-2 spike protein from the exhaled breath by sampling the target analyte into the collector, followed by its detection out of the N95 face mask using a magnetic bead-based electrochemical immunosensor. This approach was designed to avoid any contact between humans and the chemicals. To simulate human exhaled breath, untreated saliva samples were nebulized on the paper collector, revealing a detection limit of 1 ng/mL and a wide linear range of 3.7-10,000 ng/mL. Additionally, the developed immunosensor exhibited high selectivity toward the SARS-CoV-2 spike protein, compared to other airborne microorganisms, and the SARS-CoV-2 nucleocapsid protein. Accuracy assessments were conducted by analyzing the simulated breath samples spiked with varying concentrations of SARS-CoV-2 spike protein, resulting in satisfactory recovery values (ranging from 97 ± 4 to 118 ± 1%). Finally, the paper-based hybrid immunosensor was successfully applied for the detection of SARS-CoV-2 in real human exhaled breath samples. The position of the collector in the N95 mask was evaluated as well as the ability of this paper-based analytical tool to identify the positive patient.

One-step synthesized multisize AuAg alloy nanoparticles with high SERS sensitivity in directly detecting SARS-CoV-2 spike protein.

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in widespread disease transmission, challenging the stability of global healthcare systems. Surface-enhanced Raman scattering (SERS) as an easy operation, fast, and low-cost technology illustrates a good potential in detecting SARS-CoV-2. In the study, one-step fabrication of gold-silver alloy nanoparticles (AuAgNPs) with adjustable metal proportions and diameters is employed as SERS substrates. The angiotensin-converting enzyme 2 (ACE2) functionalized AuAgNPs are applied as sensor surfaces to detect SARS-CoV-2 S protein. By optimizing the SERS substrates, ACE2/Au35Ag65NPs illustrate higher performance in detecting the SARS-CoV-2 S protein with a limit of detection (LOD) of 10 fg/mL in both phosphate-buffered saline (PBS) and pharyngeal swabs solution (PSS). It also provides excellent reproducibility with a relative standard deviation (RSD) of 7.7 % and 7.9 %, respectively. This easily preparable and highly reproducible SERS substrate has good potential in the practical application of detecting SARS-CoV-2.

Weak Value Amplification Based Optical Sensor for High Throughput Real-Time Immunoassay of SARS-CoV-2 Spike Protein.

The demand for accurate and efficient immunoassays calls for the development of precise, high-throughput analysis methods. This paper introduces a novel approach utilizing a weak measurement interface sensor for immunoassays, offering a solution for high throughput analysis. Weak measurement is a precise quantum measurement method that amplifies the weak value of a system in the weak interaction through appropriate pre- and post-selection states. To facilitate the simultaneous analysis of multiple samples, we have developed a chip with six flow channels capable of conducting six immunoassays concurrently. We can perform real-time immunoassay to determine the binding characteristics of spike protein and antibody through real-time analysis of the flow channel images and calculating the relative intensity. The proposed method boasts a simple structure, eliminating the need for intricate nano processes. The spike protein concentration and relative intensity curve were fitted using the Log-Log fitting regression equation, and R2 was 0.91. Utilizing a pre-transformation approach to account for slight variations in detection sensitivity across different flow channels, the present method achieves an impressive limit of detection(LOD) of 0.85 ng/mL for the SARS-CoV-2 the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, with a system standard deviation of 5.61. Furthermore, this method has been successfully verified for monitoring molecular-specific binding processes and differentiating binding capacities.

Sensitivity-improved SERS detection of SARS-CoV-2 spike protein by Au NPs/COFs integrated with catalytic-hairpin-assembly amplification technology.

BACKGROUND: The COVID-19 pandemic, caused by the novel coronavirus, has had a profound impact on global health and economies worldwide. This unprecedented crisis has affected individuals, communities, and nations in diverse manners. Developing simple and accurate diagnostic methods is an imperative task for frequent testing to mitigate the spread of the virus. Among these methods, SARS-CoV-2 antigen tests in clinical specimens have emerged as a promising diagnostic method for COVID-19 due to their sensitive and accurate detection of spike (S) protein, which plays a crucial role in viral infection initiation. RESULTS: In this work, a dual-signal amplification surface enhanced Raman scattering (SERS)-based S protein biosensor was constructed based on Au NPs/COFs and enzyme-free catalytic hairpin assembly (CHA) amplification method. The approach relies on a released free DNA sequence (T), which is generated from the competition reaction between Aptamer/T and Aptamer/S protein, to trigger a CHA reaction. Due to the high binding affinity and selectivity between the S protein and its aptamer, CHA process was triggered with the maximum SERS tags (H2-conjugated Au@4-mercaptobenzonitrile@Ag) anchored onto Au NPs/COFs substrate surface. This SERS platform could detect the S protein at concentrations with high sensitivity (limit of detection = 3.0 × 10-16 g/mL), wide detection range (1 × 10-16 to 1 × 10-11 g/mL), acceptable reproducibility (relative standard deviation = 7.01 %) and excellent specificity. The biosensor was also employed to detect S protein in artificial human salivas. SIGNIFICANCE: Thus, this study not only developed a novel Au NPs/COFs substrate exhibiting strong SERS enhancement ability and high reproducibility, but also proposed a promising dual-signal amplification SERS-based diagnostic method for COVID-19, holding immense potential for the detection of a wide range of antigens and infectious diseases in future applications.

Ultrafast and highly sensitive detection of SARS-CoV-2 spike protein by field-effect transistor graphene-based biosensors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), etiological agent for the coronavirus disease 2019 (COVID-19), has resulted in over 775 million global infections. Early diagnosis remains pivotal for effective epidemiological surveillance despite the availability of vaccines. Antigen-based assays are advantageous for early COVID-19 detection due to their simplicity, cost-effectiveness, and suitability for point-of-care testing (PoCT). This study introduces a graphene field-effect transistor-based biosensor designed for high sensitivity and rapid response to the SARS-CoV-2 spike protein. By functionalizing graphene with monoclonal antibodies and applying short-duration gate voltage pulses, we achieve selective detection of the viral spike protein in human serum within 100 µs and at concentrations as low as 1 fg ml-1, equivalent to 8 antigen molecules perµl of blood. Furthermore, the biosensor estimates spike protein concentrations in serum from COVID-19 patients. Our platform demonstrates potential for next-generation PoCT antigen assays, promising fast and sensitive diagnostics for COVID-19 and other infectious diseases.

Bismuthene - Tetrahedral DNA nanobioconjugate for virus detection.

In this work, we present an electrochemical sensor for fast, low-cost, and easy detection of the SARS-CoV-2 spike protein in infected patients. The sensor is based on a selected combination of nanomaterials with a specific purpose. A bioconjugate formed by Few-layer bismuthene nanosheets (FLB) and tetrahedral DNA nanostructures (TDNs) is immobilized on Carbon Screen-Printed Electrodes (CSPE). The TDNs contain on the top vertex an aptamer that specifically binds to the SARS-CoV-2 spike protein, and a thiol group at the three basal vertices to anchor to the FLB. The TDNs are also marked with a redox indicator, Azure A (AA), which allows the direct detection of SARS-CoV-2 spike protein through changes in the current intensity of its electrolysis before and after the biorecognition reaction. The developed sensor can detect SARS-CoV-2 spike protein with a detection limit of 1.74 fg mL-1 directly in nasopharyngeal swab human samples. Therefore, this study offers a new strategy for rapid virus detection since it is versatile enough for different viruses and pathogens.

On-mask detection of SARS-CoV-2 related substances by surface enhanced Raman scattering.

We have developed a convenient surface-enhanced Raman scattering (SERS) platform based on vertical standing gold nanowires (v-AuNWs) which enabled the on-mask detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) related substances such as the Spike-1 protein and the corresponding pseudo-virus. The Spike-1 protein was clearly distinguished from BSA protein with an accuracy above 99 %, and the detection limit could be achieved down to 0.01 µg/mL. Notably, a similar accuracy was achieved for the pseudo-SARS-CoV-2 (pSARS-2) virus as compared to the pseudo-influenza H7N9 (pH7N9) virus. The sensing strategy and setups could be easily adapted to the real SARS-CoV-2 virus and other highly contagious viruses. It provided a promising way to screen the virus carriers by a fast evaluation of their wearing v-AuNWs integrated face-mask which was mandatory during the pandemic.

A portable transistor immunosensor for fast identification of porcine epidemic diarrhea virus.

Widespread distribution of porcine epidemic diarrhea virus (PEDV) has led to catastrophic losses to the global pig farming industry. As a result, there is an urgent need for rapid, sensitive and accurate tests for PEDV to enable timely and effective interventions. In the present study, we develop and validate a floating gate carbon nanotubes field-effect transistor (FG CNT-FET)-based portable immunosensor for rapid identification of PEDV in a sensitive and accurate manner. To improve the affinity, a unique PEDV spike protein-specific monoclonal antibody is prepared by purification, and subsequently modified on FG CNT-FET sensor to recognize PEDV. The developed FET biosensor enables highly sensitive detection (LoD: 8.1 fg/mL and 100.14 TCID50/mL for recombinant spike proteins and PEDV, respectively), as well as satisfactory specificity. Notably, an integrated portable platform consisting of a pluggable FG CNT-FET chip and a portable device can discriminate PEDV positive from negative samples and even identify PEDV and porcine deltacoronavirus within 1 min with 100% accuracy. The portable sensing platform offers the capability to quickly, sensitively and accurately identify PEDV, which further points to a possibility of point of care (POC) applications of large-scale surveillance in pig breeding facilities.

Study of V2CTx-MXene Based Immunosensor for Sensitive Label-Free Impedimetric Detection of SARS-CoV-2 Spike Protein.

Rapid and reliable immunosensing is undoubtedly one of the priorities in the efficient management and combat against a pandemic, as society has experienced with the SARS-CoV-2 outbreak; simple and cost-effective sensing strategies are at the forefront of these efforts. In this regard, 2D-layered MXenes hold great potential for electrochemical biosensing due to their attractive physicochemical properties. Herein, we present a V2CTx MXene-based sensing layer as an integral part of a label-free immunosensor for sensitive and selective detection of the SARS-CoV-2 spike protein. The sensor was fabricated on a supporting screen-printed carbon electrode using Nafion as an immobilizing agent for MXene and glutaraldehyde, the latter enabling effective binding of protein A for further site-oriented immobilization of anti-SARS-CoV-2 antibodies. A thorough structural analysis of the sensor architecture was carried out, and several key parameters affecting the fabrication and analytical performance of the immunosensor were investigated and optimized. The immunosensor showed excellent electroanalytical performance in combination with an impedimetric approach and exhibited a low detection limit of only 45 fM SARS-CoV-2 spike protein. Its practical applicability was successfully demonstrated by measuring the spike protein in a spiked artificial nasopharyngeal fluid sample.

Disposable graphene-oxide screen-printed electrode integrated with portable device for detection of SARS-CoV-2 in clinical samples.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis is the need of the hour, as cases are persistently increasing, and new variants are constantly emerging. The ever-changing nature of the virus leading to multiple variants, has brought an imminent need for early, accurate and rapid detection methods. Herein, we have reported the design and fabrication of Screen-Printed Electrodes (SPEs) with graphene oxide (GO) as working electrode and modified with specific antibodies for SARS-CoV-2 Receptor Binding Domain (RBD). Flexibility of design, and portable nature has made SPEs the superior choice for electrochemical analysis. The developed immunosensor can detect RBD as low as 0.83 fM with long-term storage capacity. The fabricated SPEs immunosensor was tested using a miniaturized portable device and potentiostat on 100 patient nasopharyngeal samples and corroborated with RT-PCR data, displayed 94 % sensitivity. Additionally, the in-house developed polyclonal antibodies detected RBD antigen of the mutated Omicron variant of SARS-CoV-2 successfully. We have not observed any cross-reactivity/binding of the fabricated immunosensor with MERS (cross-reactive antigen) and Influenza A H1N1 (antigen sharing common symptoms). Hence, the developed SPEs sensor may be applied for bedside point-of-care diagnosis of SARS-CoV-2 using miniaturized portable device, in clinical samples.

Magnetic metal-organic frameworks as sensitive aptasensors for coronavirus spike protein.

Electrochemical biosensors, known for their low cost, sensitivity, selectivity, and miniaturization capabilities, are ideal for point-of-care devices. The magnetic metal-organic framework (MMOF), synthesized using the in-situ growth method, consists of ferric salt, magnetic nanoparticles, histidine, and benzene tetracarboxylic acid. MMOF was sequentially modified with aptamer-biotin and streptavidin-horseradish peroxidase, serving as a detector for spike protein and a transducer converting electrochemical signals using H2O2-hydroquinone on a screen-printed electrode. MMOF facilitates easy washing and homogeneous deposition on the working electrode with a magnet, enhancing sensitivity and reducing noise. The physical and electrochemical properties of the modified MMOFs were thoroughly characterized using various analytical techniques. The aptasensors' performance achieved a detection limit of 6 pM for voltammetry and 5.12 pM for impedance spectroscopy in human serum samples. This cost-effective, portable MMOF platform is suitable for rapid point-of-care testing for SARS-CoV-2 spike proteins.

Rapid and simple viral protein detection by functionalized 2D MoS2/graphene electrochemiluminescence aptasensor.

In this work we present the development of an electrochemiluminescence aptasensor based on electrografting molybdenum disulphide nanosheets functionalized with diazonium salt (MoS2-N2+) upon screen-printed electrodes of graphene (SPEs GPH) for viral proteins detection. In brief, this aptasensor consists of SPEs GPH electrografted with MoS2-N2+ and modified with a thiolated aptamer, which can specifically recognize the target protein analyte. In this case, we have used SARS-CoV-2 spike protein as model protein. Electrochemiluminescence detection was performed by using the [Ru(bpy)3]2+/TPRA (tripropylamine) system, which allows the specific detection of the SARS-CoV-2 spike protein easily and rapidly with a detection limit of 9.74 fg/mL and a linear range from 32.5 fg/mL to 50.0 pg/mL. Moreover, the applicability of the aptasensor has been confirmed by the detection of the protein directly in human saliva samples. Comparing our device with a traditional saliva antigen test, our aptasensor can detect the spike protein even when the saliva antigen test gives a negative result.

Self-Assembly of Single-Virus SERS Hotspots for Highly Sensitive In Situ Detection of SARS-CoV-2 on Solid Surfaces.

Microbial surface transmission has aroused great attention since the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Developing a simple in situ detection method for viruses on solid surfaces is of great significance for timely public health surveillance. Taking advantage of the natural structure of SARS-CoV-2, we reported the assembly of Au@AgNPs on the surface of a single virus by the specific aptamer-spike protein interaction. Multiple hotspots can be created between the neighboring Au@AgNPs for the highly sensitive surface-enhanced Raman scattering (SERS) detection of SARS-CoV-2. Using two different aptamers labeled with Cy3 and Au@AgNPs, in situ SERS detection of pseudotyped SARS-CoV-2 (PSV) on packaging surfaces was achieved within 20 min, with a detection limit of 5.26 TCID50/mL. For the blind testing of 20 PSV-contaminated packaging samples, this SERS aptasensor had a sensitivity of 100% and an accuracy of 100%. This assay has been successfully applied to in situ detection of PSV on the surfaces of different packaging materials, suggesting its potential applicability.

Construction of AlGaN/GaN high-electron-mobility transistor-based biosensor for ultrasensitive detection of SARS-CoV-2 spike proteins and virions.

The COVID-19 pandemic has highlighted the need for rapid and sensitive detection of SARS-CoV-2. Here, we report an ultrasensitive SARS-CoV-2 immunosensor by integration of an AlGaN/GaN high-electron-mobility transistor (HEMT) and anti-SARS-CoV-2 spike protein antibody. The AlGaN/GaN HEMT immunosensor has demonstrated the capability to detect SARS-CoV-2 spike proteins at an impressively low concentration of 10-22 M. The sensor was also applied to pseudoviruses and SARS-CoV-2 ΔN virions that display the Spike proteins with a single virion particle sensitivity. These features validate the potential of AlGaN/GaN HEMT biosensors for point of care tests targeting SARS-CoV-2. This research not only provides the first HEMT biosensing platform for ultrasensitive and label-free detection of SARS-CoV-2.

Rapid detection of SARS-CoV-2 spike protein using a magnetic-assisted electrochemical biosensor based on functionalized CoFe2O4 magnetic nanomaterials.

The outbreak of novel coronavirus pneumonia (COVID-19) in 2019 has garnered widespread attention. The virus exhibits high contagiousness, and in certain cases, it can lead to recurrent infections. Therefore, it is imperative to develop portable, sensitive, and accurate sensors to promptly detect infected individuals, control the virus's transmission, and determine suitable treatment strategies. In this study, we proposed a magnetically-assisted method employing CFO@CS-Au MNP as the substrate material, which was functionalized with human angiotensin-converting enzyme (ACE2) for efficient capture of SARS-CoV-2 spike protein in solution. Subsequently, the captured protein was sensitively detected through differential pulse voltammetry (DPV) electrical analysis. The linear detection range of the labeled GCE/MNP/GA/ACE2/BSA electrochemical sensor is from 1 pg/mL to 10 µg/mL, with a minimum detection limit of 0.15 pg/mL. Furthermore, the fabricated GCE/MNP/GA/ACE2/BSA sensor achieved satisfactory recoveries of SARS-CoV-2 spike protein in saliva and nasal swab samples within 10 min. These results indicate that this magnetically-assisted biosensor has established a solid foundation for the swift on-site detection of COVID-19.

Development and validation of a rapid and easy-to-perform point-of-care lateral flow immunoassay (LFIA) for the detection of SARS-CoV-2 spike protein.

Development and validation of rapid and easy-to-perform diagnostics continue to be a high priority during the current COVID-19 pandemic. Although vaccines are now widely available, early detection and consistent transmission control provide ideal means to mitigate the spread of SARS-CoV-2. Nucleic acid-based real-time PCR tests are widely acknowledged as the gold standard for reliable diagnosis of COVID-19 infection. These tests are based on detecting viable or nonviable viral nucleic acids. SARS-CoV-2 spike protein is an alternative and ideal target for SARS-CoV-2 diagnosis in the early phase of infection, but point-of-care kits to detect the SARS-CoV-2 spike protein are limited. Here we describe a rapid and convenient method based on Lateral Flow Immunoassay (LFIA) to detect SARS-CoV-2 spike proteins, including SARS-CoV-2 variants (A.23.1, B.1.1.1, 1.617.2, B.1.1.7, B.1.351, P.1, N501Y, R.1, P681H, P3, UK, and South African) within 5 to 10 minutes. We generated highly specific monoclonal antibodies (mAbs) against rationally designed SARS-CoV-2 spike protein. Matched pair mAbs were selected by epitope mapping and employed as antigen capture reagents by spotting onto a nitrocellulose membrane and as detector reagents by conjugation with colloidal gold nanoparticles. We evaluated the performance of the LFIA using recombinant spike proteins of SARS-CoV-2 and several SARS-CoV-2 variants. The specificity of the LFIA was assessed using heat-inactivated SARS-CoV-2 and related human coronaviruses (HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63) and an FDA-approved respiratory pathogens (RP) panel. The assay exhibited 98% specificity and acceptable performance with respect to the minimum limit of detection (25 ng/test) in validation tests. This new LFIA provides improved performance for the early diagnosis of SARS-CoV-2, particularly for home monitoring and in situations with limited access to molecular methods.

Freestanding Laser-Induced Graphene Ultrasensitive Resonative Viral Sensors.

Early and reliable detection of an infectious viral disease is critical to accurately monitor outbreaks and to provide individuals and health care professionals the opportunity to treat patients at the early stages of a disease. The accuracy of such information is essential to define appropriate actions to protect the population and to reduce the likelihood of a possible pandemic. Here, we show the fabrication of freestanding laser-induced graphene (FLIG) flakes that are highly sensitive sensors for high-fidelity viral detection. As a case study, we show the detection of SARS-CoV-2 spike proteins. FLIG flakes are nonembedded porous graphene foams ca. 30 µm thick that are generated using laser irradiation of polyimide and can be fabricated in seconds at a low cost. Larger pieces of FLIG were cut forming a cantilever, used as suspended resonators, and characterized for their electromechanics behavior. Thermomechanical analysis showed FLIG stiffness comparable to other porous materials such as boron nitride foam, and electrostatic excitation showed amplification of the vibrations at frequencies in the range of several kilo-hertz. We developed a protocol for aqueous biological sensing by characterizing the wetting dynamic response of the sensor in buffer solution and in water, and devices functionalized with COVID-19 antibodies specifically detected SARS-CoV-2 spike protein binding, while not detecting other viruses such as MS2. The FLIG sensors showed a clear mass-dependent frequency response shift of ∼1 Hz/pg, and low nanomolar concentrations could be detected. Ultimately, the sensors demonstrated an outstanding limit of detection of 2.63 pg, which is equivalent to as few as ∼5000 SARS-CoV-2 viruses. Thus, the FLIG platform technology can be utilized to develop portable and highly accurate sensors, including biological applications where the fast and reliable protein or infectious particle detection is critical.

Comparison of the measured values of quantitative SARS-CoV-2 spike antibody assays.

BACKGROUND: The concentration of antibodies against the SARS-CoV-2 spike protein is frequently being measured for clinical and epidemiological purposes. The aim of this study was to examine whether the results of different quantitative SARS-CoV-2 spike antibody assays are comparable. MATERIAL AND METHODS: The Siemens SARS-CoV-2 IgG, Abbott SARS-CoV-2 IgG II Quant, Roche ElecsysT Anti-SARS-CoV-2 S, and Euroimmun Anti-SARS-CoV-2-QuantiVac assay were compared with 110 sera from patients 6-9 months after SARS-CoV-2 infection and the WHO First International SARS-CoV-2 antibody standard 20/136. The antibody values were converted into WHO binding antibody units (BAU)/ml. The diagnostic sensitivity of the assays was determined and the antibody values were compared. RESULTS: The diagnostic sensitivity ranged from 57.3% (Euroimmun) to 100% (Roche). The antibody concentration values of different assays correlated with Pearson coefficients of correlation between 0.729 and 0.953. The geometric mean antibody values of the Abbott, Siemens and Euroimmun assay varied by a factor of 1.1-1.2. The geometric mean antibody values of the Roche assay were 2.4-2.8 times higher than those from the other assays. The assays yielded varying results with the WHO International antibody standard. CONCLUSIONS: The quantitative SARS-CoV-2 antibody assays from Abbott, Siemens, Roche and Euroimmun correlate strongly but differ in the antibody concentrations. Therefore, the same assay should be used when testing patients repeatedly. In addition, the name of the assay used and the manufacturer should be indicated along with the test results.

CaZnO-based nanoghosts for the detection of ssDNA, pCRISPR and recombinant SARS-CoV-2 spike antigen and targeted delivery of doxorubicin.

Overexpression of proteins/antigens and other gene-related sequences in the bodies could lead to significant mutations and refractory diseases. Detection and identification of assorted trace concentrations of such proteins/antigens and/or gene-related sequences remain challenging, affecting different pathogens and making viruses stronger. Correspondingly, coronavirus (SARS-CoV-2) mutations/alterations and spread could lead to overexpression of ssDNA and the related antigens in the population and brisk activity in gene-editing technologies in the treatment/detection may lead to the presence of pCRISPR in the blood. Therefore, the detection and evaluation of their trace concentrations are of critical importance. CaZnO-based nanoghosts (NGs) were synthesized with the assistance of a high-gravity technique at a 1,800 MHz field, capitalizing on the use of Rosmarinus officinalis leaf extract as the templating agent. A complete chemical, physical and biological investigation revealed that the synthesized NGs presented similar morphological features to the mesenchymal stem cells (MSCs), resulting in excellent biocompatibility, interaction with ssDNA- and/or pCRISPR-surface, through various chemical and physical mechanisms. This comprise the unprecedented synthesis of a fully inorganic nanostructure with behavior that is similar to MSCs. Furthermore, the endowed exceptional ability of inorganic NGs for detective sensing/folding of ssDNA and pCRISPR and recombinant SARS-CoV-2 spike antigen (RSCSA), along with in-situ hydrogen peroxide detection on the HEK-293 and HeLa cell lines, was discerned. On average, they displayed a high drug loading capacity of 55%, and the acceptable internalizations inside the HT-29 cell lines affirmed the anticipated MSCs-like behavior of these inorganic-NGs.