Suchergebnisse

Trimetallic selenides as bifunctional electrocatalysts for oxygen evolution reaction (OER) and urea oxidation reaction (UOR) have rarely been reported. Herein, we successfully synthesized nickel-iron-cobalt diselenides on the nickel foam (NiFeCoSe2) by a one-step electrodeposition method. The as-prepared NiFeCoSe2 nanosheets on nickel foam (NF) exhibited significantly improved electrocatalytic performance and stability in a highly alkaline medium (1 M KOH) with and without 0.33 M urea. In particular, the obtained NiFeCoSe2 only requires a potential of 1.52 V (vs. RHE) for OER and 1.37 V (vs. RHE) for UOR to achieve a current density of 50 mA cm−2, along with a stability of 30 h. This was attributed to the unique interconnected nanosheets, binder-free in-situ selenium electrodeposition, synergistic effect, and strong electron interaction of Ni, Fe, Co, and Se elements. This study provides a new avenue for the construction of multimetal selenide electrocatalysts with excellent properties for the oxidation of water and urea. ; This work was supported by the Human Resources Development Program (No. 20194030202470) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korean Government Ministry of Trade, Industry, and Energy and supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2018R1A6A1A03024334).

The antigen-based rapid diagnostic test (Ag-RDT) using saliva specimens is fast, noninvasive, and suitable for SARS-CoV-2 self-testing, unlike nasopharyngeal swab (NPS) testing. We evaluated a novel Beanguard gargle (BG)-based virus collection method that can be applied to Ag-RDT as an alternative to the current RT-PCR with an NPS for early diagnosis of COVID-19. This clinical trial comprised 102 COVID-19-positive patients hospitalized after a governmental screening process and 100 healthy individuals. Paired NPS and BG-based saliva specimens from COVID-19 patients and healthy individuals were analyzed using NPS-RT-PCR, BG-RT-PCR, and BG-Ag-RDTs, whose diagnostic performance for detecting SARS-CoV-2 was compared. BG-Ag-RDTs showed high sensitivity (97.8%) and specificity (100%) in 45 patients within 6 days of illness and detected all cases of SARS-CoV-2 Alpha and Delta variants. In 11 asymptomatic active COVID-19 cases, both BG-Ag-RDTs and BG-RT-PCR showed sensitivities and specificities of 100%. Sensitivities of BG-Ag-RDT and BG-RT-PCR toward salivary viral detection were highly concordant, with no discrimination between symptomatic (97.0%), asymptomatic (100%), or SARS-CoV-2 variant (100%) cases. The intermolecular interactions between SARS-CoV-2 spike proteins and truncated canavalin, an active ingredient from the bean extract (BE), were observed in terms of physicochemical properties. The detachment of the SARS-CoV-2 receptor-binding domain from hACE2 increased as the BE concentration increased, allowing the release of the virus from hACE2 for early diagnosis. Using BG-based saliva specimens remarkably enhances the Ag-RDT diagnostic performance as an alternative to NPS and enables noninvasive, rapid, and accurate COVID-19 self-testing and mass screening, supporting efficient COVID-19 management. IMPORTANCE An Ag-RDT is less likely to be accepted as an initial test method for early diagnosis owing to its low sensitivity. However, our self-collection method, Ag-RDT using BG-based saliva specimens, showed ...