Ultra-Trace Monitoring of Methylene Blue Degradation via AgNW-Based SERS: Toward Sustainable Advanced Oxidation Water Treatment

Sustainability, Journal Year: 2025, Volume and Issue: 17(10), P. 4448 - 4448

Published: May 14, 2025

Methylene blue (MB), a widely used industrial dye, is persistent pollutant with documented toxicity to aquatic organisms and potential health risks humans, even at ultra-trace levels. Conventional monitoring techniques such as UV–Vis spectroscopy fluorescence emission suffer from limited sensitivity, typically failing detect MB below ~10−7 M. In this study, we introduce surface-enhanced Raman (SERS) platform based on silver nanowire (AgNW) substrates that enables detection over an unprecedented dynamic range—from 1.5 × 10−4 M down 10−16 mapping confirmed the presence of individual signal hot spots lowest concentration, consistent theoretical number analyte molecules in probed area, thereby demonstrating near-single-molecule capability. The calculated enhancement factors reached up 1.90 1012, among highest reported for SERS-based platforms. A semi-quantitative calibration curve was established spanning twelve orders magnitude, successfully applied monitor degradation during two advanced oxidation processes (AOPs): TiO2 nanotube-mediated photocatalysis under UV irradiation atmospheric-pressure dielectric barrier discharge (DBD) plasma treatment. While rapidly lost sensitivity process, SERS continued characteristic peak ~1626 cm−1 throughout entire treatment duration. These signals revealed residual or partially degraded aromatic intermediates remained undetectable by conventional optical methods. results underscore ability AgNW-based provide ultra-sensitive, molecular-level insights into transformation pathways, enabling time-resolved tracking kinetics validating efficiency. This work highlights importance integrating AOPs powerful complementary strategy environmental water purification technologies. By delivering low-cost sensor (<USD 0.16 per test) promoting reagent-free methods, study directly advances SDG 6 (Clean Water Sanitation) 12 (Responsible Consumption Production).

Language: Английский

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Physical and chemical characteristics of plasma-activated water generated by hybrid dielectric barrier discharge and gliding arc discharge

Journal of Physics D Applied Physics, Journal Year: 2024, Volume and Issue: 57(41), P. 415204 - 415204

Published: July 22, 2024

Abstract This research explores the synergistic application of Dielectric Barrier Discharge (DBD) and Gliding Arc Plasma Jet (GAPJ) in a Hybrid (HPD) setup for enhanced water activation. The HPD system demonstrated balanced sustained generation reactive oxygen nitrogen species (RONS), maintaining efficiency at higher specific input energy (SIE) values. Comparative analyses with DBD GAPJ systems highlighted superior performance generating RONS modifying water’s molecular structure. Key observations included decrease pH an increase oxidation-reduction potential, total dissolved solids, conductivity, stabilizing beyond 5 l min −1 airflow 10 treatment. UV−Vis spectroscopy identified nitrites, nitrates, hydrogen peroxide, nitrous acid, while Raman captured shifts vibrational modes, particularly librational O–H stretching bands. These changes correlated alterations concentrations levels. Overall, emerged as versatile efficient approach plasma-activated water, suitable applications microbial deactivation, surface sterilization, electrocatalytic process optimization, offering stable continuous production across range SIE

Language: Английский

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Proposing an Affordable Plasma Device for Polymer Surface Modification and Microbial Inactivation

Molecules, Journal Year: 2024, Volume and Issue: 29(17), P. 4270 - 4270

Published: Sept. 9, 2024

This study proposes an affordable plasma device that utilizes a parallel-plate dielectric barrier discharge geometry with metallic mesh electrode, featuring straightforward 3D-printed design. Powered by high-voltage supply adapted from cosmetic device, it operates on atmospheric air, eliminating the need for gas flux. Surface modification of polyethylene treated this was characterized and showed elemental composition after 15 min treatment decreased amount C to ~80 at% due insertion O (~15 at%). Tested against

Language: Английский

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Sputter deposited silver film as an alternative tool for Raman signal enhancement in plasma-activated water

Vibrational Spectroscopy, Journal Year: 2024, Volume and Issue: unknown, P. 103765 - 103765

Published: Dec. 1, 2024

Language: Английский

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