Clinical Trial: Magnetoplasmonic ELISA for Urine-based Active Tuberculosis Detection and Anti-Tuberculosis Therapy Monitoring

Smart Nanozymes for Diagnosis of Bacterial Infection: The Next Frontier from Laboratory to Bedside Testing

The global spread of infectious diseases caused by pathogenic bacteria significantly poses public health concerns, and methods for sensitive, selective, and facile diagnosis of bacteria can efficiently prevent deterioration and further spreading of the infections. The advent of nanozymes has broadened the spectrum of alternatives for diagnosing bacterial infections. Compared to natural enzymes, nanozymes exhibit the same enzymatic characteristics but offer greater economic efficiency, enhanced durability, and adjustable dimensions. The importance of early diagnosis of bacterial infection and conventional diagnostic approaches is introduced. Subsequently, the review elucidates the definition, properties, and catalytic mechanism of nanozymes. Eventually, the detailed application of nanozymes in detecting bacteria is explored, highlighting their utilization as biosensors that allow for accelerated and highly sensitive identification of bacterial infections and reflecting on the potential of nanozyme-based bacterial detection as a point-of-care testing (POCT) tool. A brief summary of obstacles and future perspectives in this field is presented at the conclusion of this review.

Operation-friendly and accurate naked-eye observation assay for fast zoonotic echinococcosis and pulmonary tuberculosis monitoring in clinics

Echinococcosis and tuberculosis are two common zoonotic diseases that can cause severe pulmonary infections. Early screening and treatment monitoring are of great significance, especially in areas with limited medical resources. Herein, we designed an operation-friendly and rapid magnetic enrichment-silver acetylene chromogenic immunoassay (Me-Sacia) to monitor the antibody. The main components included secondary antibody-modified magnetic nanoparticles (MNP-Ab2) as capture nanoparticles, specific peptide (EG95 or CFP10)-modified silver nanoparticles (AgNP-PTs) as detection nanoparticles, and alkyne-modified gold nanoflowers as chromogenic nanoparticles. Based on the magnetic separation and plasma luminescence techniques, Me-Sacia could completely replace the colorimetric assay of biological enzymes. It reduced the detection time to approximately 1 h and simplified the labor-intensive and equipment-intensive processes associated with conventional ELISA. Meanwhile, the Me-Sacia showed universality for various blood samples and intuitive observation with the naked eye. Compared to conventional ELISA, Me-Sacia lowered the detection limit by approximately 96.8 %, increased the overall speed by approximately 15 times, and improved sensitivity by approximately 7.2 %, with a 100 % specificity and a coefficient of variation (CV) of less than 15 %.

Magnetically boosted 1D photoactive microswarm for COVID-19 face mask disruption

The recent COVID-19 pandemic has resulted in the massive discard of pandemic-related plastic wastes, causing serious ecological harm and a high societal burden. Most single-use face masks are made of synthetic plastics, thus their careless disposal poses a direct threat to wildlife as well as potential ecotoxicological effects in the form of microplastics. Here, we introduce a 1D magnetic photoactive microswarm capable of actively navigating, adhering to, and accelerating the degradation of the polypropylene microfiber of COVID-19 face masks. 1D microrobots comprise an anisotropic magnetic core (Fe₃O₄) and photocatalytic shell (Bi₂O₃/Ag), which enable wireless magnetic maneuvering and visible-light photocatalysis. The actuation of a programmed rotating magnetic field triggers a fish schooling-like 1D microswarm that allows active interfacial interactions with the microfiber network. The follow-up light illumination accelerates the disruption of the polypropylene microfiber through the photo-oxidative process as corroborated by morphological, compositional, and structural analyses. The active magnetic photocatalyst microswarm suggests an intriguing microrobotic solution to treat various plastic wastes and other environmental pollutants.

Advancing personalized medicine for tuberculosis through the application of immune profiling

While early and precise diagnosis is the key to eliminating tuberculosis (TB), conventional methods using culture conversion or sputum smear microscopy have failed to meet demand. This is especially true in high-epidemic developing countries and during pandemic-associated social restrictions. Suboptimal biomarkers have restricted the improvement of TB management and eradication strategies. Therefore, the research and development of new affordable and accessible methods are required. Following the emergence of many high-throughput quantification TB studies, immunomics has the advantages of directly targeting responsive immune molecules and significantly simplifying workloads. In particular, immune profiling has been demonstrated to be a versatile tool that potentially unlocks many options for application in TB management. Herein, we review the current approaches for TB control with regard to the potentials and limitations of immunomics. Multiple directions are also proposed to hopefully unleash immunomics' potential in TB research, not least in revealing representative immune biomarkers to correctly diagnose TB. The immune profiles of patients can be valuable covariates for model-informed precision dosing-based treatment monitoring, prediction of outcome, and the optimal dose prediction of anti-TB drugs.

Magnetofluoro-Immunosensing Platform Based on Binary Nanoparticle-Decorated Graphene for Detection of Cancer Cell-Derived Exosomes

Multi-functionalized carbon nanomaterials have attracted interest owing to their excellent synergic properties, such as plasmon resonance energy transfer and surface-enhanced Raman scattering. Particularly, nanoparticle (NP)-decorated graphene (GRP) has been applied in various fields. In this study, silver NP (AgNP)- and magnetic iron oxide NP (IONP)-decorated GRP were prepared and utilized as biosensing platforms. In this case, AgNPs and GRP exhibit plasmonic properties, whereas IONPs exhibit magnetic properties; therefore, this hybrid nanomaterial could function as a magnetoplasmonic substrate for the magnetofluoro-immunosensing (MFI) system. Conversely, exosomes were recently considered high-potential biomarkers for the diagnosis of diseases. However, exosome diagnostic use requires complex isolation and purification methods. Nevertheless, we successfully detected a prostate-cancer-cell-derived exosome (PC-exosome) from non-purified exosomes in a culture media sample using Ag/IO-GRP and dye-tetraspanin antibodies (Ab). First, the anti-prostate-specific antigen was immobilized on the Ag/IO-GRP and it could isolate the PC-exosome from the sample via an external magnetic force. Dye-tetraspanin Ab was added to the sample to induce the sandwich structure. Based on the number of exosomes, the fluorescence intensity from the dye varied and the system exhibited highly sensitive and selective performance. Consequently, these hybrid materials exhibited excellent potential for biosensing platforms.

Pt-embodiment ZIF-67-derived nanocage as enhanced immunoassay for infectious virus detection

A facile and general strategy has been employed to develop highly-active nanozyme for immunoassay purposes. The hollow nanostructure of the Co₃O₄ nanocages (NCs) was anchoring the platinum nanoparticles (PtNPs) enclosed by the exposed oxides framework nd formed PtNPs@Co₃O₄ NCs. The embodiment of PtNPs was considered an ideal hybrid nanozyme that efficiently catalyzed the oxidation of the substrate molecules with enhanced activity. The PtNPs@Co₃O₄ NCs were revisited and repurposed on showing its nanozyme's activity with optimization done for the immunoassay platform. The embodiment of 32.44% Pt in the hollow nanostructures demonstrated the highest signal-to-noise responses in the immunoassay. In addition, the stepwise analysis highlighted the enhancement factor of the nanocages' catalytic mechanism. Based on their catalytic activity, these nanocages have been demonstrated to enable sub-femtogram level biosensing of norovirus-like particles (NoV-LPs) with highly selective signals in the capture-detect immunoassay format. The detection limit of the prepared immunoassay achieved 33.52 viral NoV copies/mL of the detection limit, which is 321-folds lower magnitude of the commercial ELISA. This nanocage's enhanced synergic catalytic properties could have great potential applications, including catalysis, biological labeling, and bioassays.

Applications of Nanozymology in the Detection and Identification of Viral, Bacterial and Fungal Pathogens

Nanozymes are synthetic nanoparticulate materials that mimic the biological activities of enzymes by virtue of their surface chemistry. Enzymes catalyze biological reactions with a very high degree of specificity. Examples include the horseradish peroxidase, lactate, glucose, and cholesterol oxidases. For this reason, many industrial uses of enzymes outside their natural environments have been developed. Similar to enzymes, many industrial applications of nanozymes have been developed and used. Unlike the enzymes, however, nanozymes are cost-effectively prepared, purified, stored, and reproducibly and repeatedly used for long periods of time. The detection and identification of pathogens is among some of the reported applications of nanozymes. Three of the methodologic milestones in the evolution of pathogen detection and identification include the incubation and growth, immunoassays and the polymerase chain reaction (PCR) strategies. Although advances in the history of pathogen detection and identification have given rise to novel methods and devices, these are still short of the response speed, accuracy and cost required for point-of-care use. Debuting recently, nanozymology offers significant improvements in the six methodological indicators that are proposed as being key in this review, including simplicity, sensitivity, speed of response, cost, reliability, and durability of the immunoassays and PCR strategies. This review will focus on the applications of nanozymes in the detection and identification of pathogens in samples obtained from foods, natural, and clinical sources. It will highlight the impact of nanozymes in the enzyme-linked immunosorbent and PCR strategies by discussing the mechanistic improvements and the role of the design and architecture of the nanozyme nanoconjugates. Because of their contribution to world health burden, the three most important pathogens that will be considered include viruses, bacteria and fungi. Although not quite seen as pathogens, the review will also consider the detection of cancer cells and helminth parasites. The review leaves very little doubt that nanozymology has introduced remarkable advances in enzyme-linked immunosorbent assays and PCR strategies for detecting these five classes of pathogens. However, a gap still exists in the application of nanozymes to detect and identify fungal pathogens directly, although indirect strategies in which nanozymes are used have been reported. From a mechanistic point of view, the nanozyme technology transfer to laboratory research methods in PCR and enzyme-linked immunosorbent assay studies, and the point-of-care devices such as electronic biosensors and lateral flow detection strips, that is currently taking place, is most likely to give rise to no small revolution in each of the six methodological indicators for pathogen detection and identification. While the evidence of widespread research reports, clinical trials and point-of-care device patents support this view, the gaps that still exist point to a need for more basic research studies to be conducted on the applications of nanozymology in pathogen detection and identification. The multidisciplinary nature of the research on the application of nanozymes in the detection and identification of pathogens requires chemists and physicists for the design, fabrication, and characterization of nanozymes; microbiologists for the design, testing and analysis of the methodologies, and clinicians or clinical researchers for the evaluation of the methodologies and devices in the clinic. Many reports have also implicated required skills in mathematical modelling, and electronic engineering. While the review will conclude with a synopsis of the impact of nanozymology on the detection and identification of viruses, bacteria, fungi, cancer cells, and helminths, it will also point out opportunities that exist in basic research as well as opportunities for innovation aimed at novel laboratory methodologies and devices. In this regard there is no doubt that there are numerous unexplored research areas in the application of nanozymes for the detection of pathogens. For example, most research on the applications of nanozymes for the detection and identification of fungi is so far limited only to the detection of mycotoxins and other chemical compounds associated with fungal infection. Therefore, there is scope for exploration of the application of nanozymes in the direct detection of fungi in foods, especially in the agricultural production thereof. Many fungal species found in seeds severely compromise their use by inactivating the germination thereof. Fungi also produce mycotoxins that can severely compromise the health of humans if consumed.

Nanobody and Nanozyme-Enabled Immunoassays with Enhanced Specificity and Sensitivity

Immunoassay as a rapid and convenient method for detecting a variety of targets has attracted tremendous interest with its high specificity and sensitivity. Among the commonly used immunoassays, enzyme-linked immunosorbent assay has been widely used as a gold standard method in various fields that consists of two main components including a recognition element and an enzyme label. With the rapid advances in nanotechnology, nanobodies and nanozymes enable immunoassays with enhanced specificity and sensitivity compared with conventional antibodies and natural enzymes. This review is focused on the applications of nanobodies and nanozymes in immunoassays. Nanobodies advantage lies in their small size, high specificity, mass expression, and high stability. Nanozymes with peroxidase, phosphatase, and oxidase activities and their applications in immunoassays are highlighted and discussed in detail. In addition, the challenges and outlooks in terms of the use of nanobodies and the development of novel nanozymes in practical applications are discussed.