Ultra-Trace Monitoring of Methylene Blue Degradation via AgNW-Based SERS: Toward Sustainable Advanced Oxidation Water Treatment DOI Open Access
Isabela Machado Horta, Nilton Francelosi Azevedo Neto, Letícia Terumi Kito

et al.

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

Hollow Au Nanoparticles for Single-Molecule Raman Spectroscopy via Synergic Electromagnetic and Chemical Enhancement Strategy DOI
Zihan Gao, Haiyao Yang, Jianzhi Zhang

et al.

Nanoscale, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The integration of a 2D WS 2 monolayer into plasmonic nanogap leads to synergistic enhancement, achieving an unprecedented Raman enhancement factor 10 14 –10 15 and ultrasensitive single-molecule SERS detection (10 −16 M).

Language: Английский

Citations

1
Ultra-Trace Monitoring of Methylene Blue Degradation via AgNW-Based SERS: Toward Sustainable Advanced Oxidation Water Treatment DOI Open Access
Isabela Machado Horta, Nilton Francelosi Azevedo Neto, Letícia Terumi Kito

et al.

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

Citations

0