Cubically cage-shaped mesoporous ordered silica for simultaneous visual detection and removal of uranium ions from contaminated seawater

Shear-induced fabrication of SiO2 nano-meshes for efficient uranium capture

The extraction of uranium from seawater and the safe treatment of wastewater containing uranium (VI) were important to ensure the sustainable development of nuclear-related energy sources. Two-dimensional silica nanomaterials have been extensively investigated in the field of uranium adsorption due to their high adsorption capacity, short equilibration times, and easily modified surface groups. However, the two-dimensional mesoporous silica nanomaterial preparation has become a challenge due to the lack of natural sheet templating agents. The reason will hinder the development of silica nanomaterials for uranium extraction. Here, the specific surface area silica nanomeshes (HSMSMs) uranium adsorbent was prepared by a high shear method to induce nanobubble formation. HSMSMs showed a high uranium adsorption capacity of 822 mg_-U/g_-abs in seawater with the uranium adsorption concentration was 50 mg/L, which was approximately 2 times higher than the conventional mesoporous silica nanomaterials. Compared to HSMSMs, the amidoxime-modified high specific surface area silica nanomesh (HSMSMs-AO) demonstrated good selectivity for U(VI), and the uranium ions uptake was 877 mg_-U/g_-abs in 50 mg/L uranium-spiked simulated seawater. Due to HSMSMs-AO's stable chemical properties and high mechanical strength, HSMSMs-AO also displayed long service life. Benefiting from the simple preparation method and high adsorption capacity of HSMSMs, HSMSMs could be a promising candidate for large-scale extraction of uranium from seawater.

Voltammetric biosensor for coronavirus spike protein using magnetic bead and screen-printed electrode for point-of-care diagnostics

The rapid spread of the novel human coronavirus 2019 (COVID-19) and its morbidity have created an urgent need for rapid and sensitive diagnostics. The real-time polymerase chain reaction is the gold standard for detecting the coronavirus in various types of biological specimens. However, this technique is time consuming, labor intensive, and expensive. Screen-printed electrodes (SPEs) can be used as point-of-care devices because of their low cost, sensitivity, selectivity, and ability to be miniaturized. The ability to detect the spike protein of COVID-19 in serum, urine, and saliva was developed using SPE aided by magnetic beads (MBs) and a portable potentiostat. The antibody-peroxidase-loaded MBs were the captured and catalytic units for the electrochemical assays. The MBs enable simple washing and homogenous deposition on the working electrode using a magnet. The assembly of the immunological MBs and the electrochemical system increases the measuring sensitivity and speed. The physical and electrochemical properties of the layer-by-layer modified MBs were systematically characterized. The performance of these immunosensors was evaluated using spike protein in the range 3.12–200 ng mL⁻¹. We achieved a limit of detection of 0.20, 0.31, and 0.54 ng mL⁻¹ in human saliva, urine, and serum, respectively. A facile electrochemical method to detect COVID-19 spike protein was developed for quick point-of-care testing.

Simple one-pot synthesis of manganese dioxide modified bamboo-derived biochar composite for uranium(VI) removal

Exploitation of bamboo-derived biochar offers a lucrative opportunity for using moso bamboo due to its short growth cycle, large quantity and universality. Novel MnO2 modified bamboo-derived biochar composites (MnO2@BBC) were...