Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection

Colloidal noble metal nanoparticle aggregates have demonstrated significant advantages in surface-enhanced Raman scattering (SERS) analysis, particularly for online detection, due to their excellent optical properties, spatial homogeneity, and fluidic compatibility. However, conventional chemically...

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Main Authors: Tianyu Zhou, Zhiyang Zhang
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Biosensors
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Online Access:https://www.mdpi.com/2079-6374/15/5/298
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author Tianyu Zhou
Zhiyang Zhang
author_facet Tianyu Zhou
Zhiyang Zhang
author_sort Tianyu Zhou
collection DOAJ
description Colloidal noble metal nanoparticle aggregates have demonstrated significant advantages in surface-enhanced Raman scattering (SERS) analysis, particularly for online detection, due to their excellent optical properties, spatial homogeneity, and fluidic compatibility. However, conventional chemically induced aggregation methods (such as salt-induced nanoparticle aggregation) suffer from uncontrolled aggregation, limited stability, and narrow detection windows, which restrict their quantitative and long-term applications. In this study, we developed a non-chemical method for fabricating stable colloidal aggregates from uniform β-cyclodextrin-stabilized silver nanoparticles (β-CD@AgNPs) via centrifugation. By precisely controlling the addition rate of silver nitrate, we synthesized β-cyclodextrin-stabilized silver nanoparticles with a uniform size. Surprisingly, these nanoparticles can form highly dispersed and homogeneous colloidal aggregates simply via centrifugation, which is completely different from the behavior of traditional ligand-modified nanoparticles. Notably, the resulting aggregates exhibit excellent SERS enhancement, enabling the sensitive detection of various dyes at nanomolar levels. Furthermore, they maintain a stable SERS signal (RSD = 6.99%) over a detection window exceeding 1 h, markedly improving signal stability and reproducibility compared with salt-induced aggregates. Additionally, using pyocyanin as a model analyte, we evaluated the quantitative performance of these aggregates (LOD = 0.2 nM), achieving satisfactory recovery (82–117%) in spiked samples of drinking water, lake water, and tap water. This study provides a facile strategy for fabricating stable colloidal SERS substrates and paves the way for the advancement of SERS applications in analytical sciences.
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spelling doaj-art-f30c8a2a2a1c43e49ac2f43e454d65722025-08-20T03:47:48ZengMDPI AGBiosensors2079-63742025-05-0115529810.3390/bios15050298Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering DetectionTianyu Zhou0Zhiyang Zhang1CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, ChinaCAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, ChinaColloidal noble metal nanoparticle aggregates have demonstrated significant advantages in surface-enhanced Raman scattering (SERS) analysis, particularly for online detection, due to their excellent optical properties, spatial homogeneity, and fluidic compatibility. However, conventional chemically induced aggregation methods (such as salt-induced nanoparticle aggregation) suffer from uncontrolled aggregation, limited stability, and narrow detection windows, which restrict their quantitative and long-term applications. In this study, we developed a non-chemical method for fabricating stable colloidal aggregates from uniform β-cyclodextrin-stabilized silver nanoparticles (β-CD@AgNPs) via centrifugation. By precisely controlling the addition rate of silver nitrate, we synthesized β-cyclodextrin-stabilized silver nanoparticles with a uniform size. Surprisingly, these nanoparticles can form highly dispersed and homogeneous colloidal aggregates simply via centrifugation, which is completely different from the behavior of traditional ligand-modified nanoparticles. Notably, the resulting aggregates exhibit excellent SERS enhancement, enabling the sensitive detection of various dyes at nanomolar levels. Furthermore, they maintain a stable SERS signal (RSD = 6.99%) over a detection window exceeding 1 h, markedly improving signal stability and reproducibility compared with salt-induced aggregates. Additionally, using pyocyanin as a model analyte, we evaluated the quantitative performance of these aggregates (LOD = 0.2 nM), achieving satisfactory recovery (82–117%) in spiked samples of drinking water, lake water, and tap water. This study provides a facile strategy for fabricating stable colloidal SERS substrates and paves the way for the advancement of SERS applications in analytical sciences.https://www.mdpi.com/2079-6374/15/5/298surface-enhanced Raman scattering (SERS)colloidal silver nanoaggregatescentrifugationβ-cyclodextrinsignal reproducibility
spellingShingle Tianyu Zhou
Zhiyang Zhang
Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
Biosensors
surface-enhanced Raman scattering (SERS)
colloidal silver nanoaggregates
centrifugation
β-cyclodextrin
signal reproducibility
title Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
title_full Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
title_fullStr Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
title_full_unstemmed Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
title_short Centrifugation-Induced Stable Colloidal Silver Nanoparticle Aggregates for Reproducible Surface-Enhanced Raman Scattering Detection
title_sort centrifugation induced stable colloidal silver nanoparticle aggregates for reproducible surface enhanced raman scattering detection
topic surface-enhanced Raman scattering (SERS)
colloidal silver nanoaggregates
centrifugation
β-cyclodextrin
signal reproducibility
url https://www.mdpi.com/2079-6374/15/5/298
work_keys_str_mv AT tianyuzhou centrifugationinducedstablecolloidalsilvernanoparticleaggregatesforreproduciblesurfaceenhancedramanscatteringdetection
AT zhiyangzhang centrifugationinducedstablecolloidalsilvernanoparticleaggregatesforreproduciblesurfaceenhancedramanscatteringdetection