Raman-based sensors represent a promising solution to enable both detection and fingerprinting of anionic pollutants in the water distribution network. Due to the weak nature of Raman scattering, a signal intensity enhancement mechanism, such as surface enhanced Raman spectroscopy (SERS), is required. Given the combination of SERS being a first layer effect and the low affinity for metallic surfaces shown by anions, functionalization of the SERS substrates using positively charged self-assembled monolayers (SAMs) is required to guarantee a strong SERS signal. In this work, the performance of three thiol-based coatings, namely, 2-mercapto-4-methyl-pyrimidine, cysteamine, and 2-dimethyl-amino-ethanethiol, is systematically compared for the detection of nitrite, nitrate, and perchlorate ions in water. For each coating, the limit of detection of those analytes is studied in combination with commercial SERS substrates. Cysteamine-coated SERS substrates are shown to provide the lowest limit of detection for the three analytes of this study. Evaluation of this coating on real drinking water samples is reported.
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http://dx.doi.org/10.1364/AO.58.009345 | DOI Listing |
Biomed Opt Express
January 2025
Key Laboratory of Optical Technology and Instrument for Medicine, Ministry of Education, University of Shanghai for Science and Technology, 200093 Shanghai, China.
Lung cancer with heterogeneity has a high mortality rate due to its late-stage detection and chemotherapy resistance. Liquid biopsy that discriminates tumor-related biomarkers in body fluids has emerged as an attractive technique for early-stage and accurate diagnosis. Exosomes, carrying membrane and cytosolic information from original tumor cells, impart themselves endogeneity and heterogeneity, which offer extensive and unique advantages in the field of liquid biopsy for cancer differential diagnosis.
View Article and Find Full Text PDFACS Sens
January 2025
The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, and Department of Chemistry, Shanghai Normal University, Shanghai 200234, P. R. China.
Microneedle (MN) sensors have great promise for food safety detection, but the rapid preparation of MNs for surface-enhanced Raman scattering (SERS) sensors with tunable and homogeneous nanoparticles remains a great challenge. To address this, a SERS sensor of gold nanoparticles@polydopamine@poly(methyl methacrylate) MN (AuNPs@PDA@PMMA-MN) was developed. The extended-Derjaguin-Landau-Verwey-Overbeek theory was applied to calculate the interaction energy between AuNPs and PDA.
View Article and Find Full Text PDFSoft Matter
January 2025
Faculty of Chemistry, Ho Chi Minh City University of Science, Vietnam National University, Ho Chi Minh City, 227 Nguyen Van Cu Street, Ward 4, District 5, Ho Chi Minh City 70000, Vietnam.
Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive analytical technique with excellent molecular specificity. However, separate pristine nanoparticles produce relatively weak Raman signals. It is necessary to focus on increasing the "hot-spot" density generated at the nanogaps between the adjacent nanoparticles (second-generation SERS hotspot), thus significantly boosting the Raman signal by creating an electromagnetic field.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
School of Science, Xihua University, Chengdu 610039 PR China. Electronic address:
Beta - stimulant, that is, β - adrenergic stimulant, also known as β - agonists, is bioactive catecholamine compounds naturally produced in animals' adrenal medulla glands that induce relaxation in asthmatic airway smooth muscles upon inhalation while also temporarily boosting athletic alertness and alleviating fatigue. However, their potential for dependency poses health risks including unnoticed exacerbation leading to severe illness or fatality prompting their inclusion on WADA's prohibited substances list. Surface - enhanced Raman spectroscopy (SERS) offers a rapid, sensitive, and label - free means for identifying characteristic peaks associated with β - agonist compounds.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Hainan Engineering Research Center of Tropical Ocean Advanced Opto-Electrical Functional Materials, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China.
Chrysoidin (CG) can be ingested into the human body through the skin and cause chronic toxicity, so the detection of CG levels in the environment is crucial. In this study, we synthesize F-Ag@ZIF-8/PVC molecular-imprinted membranes (FZAP-MIM) by an innovative combination of SERS detection, membrane separation, and a molecular-imprinted technique in order to perform the analysis of CG in water. The plasmonic MOF material as a SERS substrate helps to enrich the target and realize the spatial overlap of the target with the nanoparticle tip "hotspot".
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