ABSTRACT
Nanoscale plasmonic hotspots play a critical role in the enhancement of molecular Raman signals, enabling the sensitive and reliable trace analysis of biomedical molecules via surface-enhanced Raman spectroscopy (SERS). However, effective and label-free SERS diagnoses in practical fields remain challenging because of clinical samples' random adsorption and size mismatch with the nanoscale hotspots. Herein, we suggest a novel SERS strategy for interior hotspots templated with protein@Au core-shell nanostructures prepared via electrochemical one-pot Au deposition. The cytochrome c and lysates of SARS-CoV-2 (SLs) embedded in the interior hotspots were successfully functionalized to confine the electric fields and generate their optical fingerprint signals, respectively. Highly linear quantitative sensitivity was observed with the limit-of-detection value of 10-1 PFU/ mL. The feasibility of detecting the targets in a bodily fluidic environment was also confirmed using the proposed templates with SLs in human saliva and nasopharyngeal swabs. These interior hotspots templated with the target analytes are highly desirable for early and on-site SERS diagnoses of infectious diseases without any labeling processes.
ABSTRACT
During the COVID-19 outbreak, fake news regarding the disease have spread at an increasing rate. Let's think, for instance, to face masks wearing related news or various home-made treatments to cure the disease. To contrast this phenomenon, the fact-checking community has intensified its efforts by producing a large number of factchecking reports. In this work, we focus on empowering knowledge-based approaches for misinformation identification with previous knowledge gathered from existing fact-checking reports. Very few works in literature have exploited the information regarding claims that have been already fact-checked. The main idea that we explore in this work is to exploit the detailed information in the COVID-19 fact check reports in order to create an extended Knowledge Graph. By analysing the graph information about the already checked claims, we can verify newly coming content more effectively. Another gap that we aim to fill is the temporal representation of the facts stored in the knowledge graph. At the best of our knowledge, this is the first attempt to associate the temporal validity to the KG relations. This additional information can be used to further enhance the validation of claims.
ABSTRACT
In recent decades, biomedical sensors based on surface-enhanced Raman spectroscopy (SERS), which reveals unique spectral features corresponding to individual molecular vibrational states, have attracted intensive attention. However, the lack of a system for precisely guiding biomolecules to active hotspot regions has impeded the broad application of SERS techniques. Herein, we demonstrate the irreversible active engineering of three-dimensional (3D) interior organo-hotspots via electrochemical (EC) deposition onto metal nanodimple (ECOMD) platforms with viral lysates. This approach enables organic seed-programmable Au growth and the spontaneous bottom-up formation of 3D interior organo-hotspots simultaneously. Because of the net charge effect on the participation rate of viral lysates, the number of interior organo-hotspots in the ECOMDs increases with increasingly positive polarity. The viral lysates embedded in the ECOMDs function as both a dielectric medium for field confinement and an analyte, enabling the highly specific and sensitive detection of SARS-CoV-2 lysates (SLs) at concentrations as low as 10-2 plaque forming unit/mL. The ECOMD platform was used to trace and detect the SLs in human saliva and diagnose of the delta-type SARS-CoV-2 in clinical environments;the results indicate that the proposed platform can provide point-of-care diagnoses of infectious diseases.