Multiplexed SERS Detection of Microcystins with Aptamer-Driven Core–Satellite Assemblies
| Autor: | Marie-Hélène Brunet, Jean-Francois Masson, Ping Wu, Chenxin Cai, Xiaojun Luo, Kevin J. Wilkinson, C. Geraldine Bazuin, Gregory Q Wallace, Xingjuan Zhao |
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| Rok vydání: | 2021 |
| Předmět: |
Silver
Materials science Nanostructure Microcystins Surface Properties Aptamer Metal Nanoparticles Nanoparticle Nanotechnology 02 engineering and technology Spectrum Analysis Raman 010402 general chemistry 01 natural sciences symbols.namesake General Materials Science Multiplex Particle Size Detection limit Aptamers Nucleotide 021001 nanoscience & nanotechnology 0104 chemical sciences symbols Gold 0210 nano-technology Science technology and society Selectivity Raman spectroscopy |
| Zdroj: | ACS Applied Materials & Interfaces. 13:6545-6556 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.0c21493 |
| Popis: | We describe surface-enhanced Raman spectroscopy (SERS) aptasensors that can indirectly detect MC-LR and MC-RR, individually or simultaneously, in natural water and in algal culture. The sensor is constructed from nanoparticles composed of successive layers of Au core-SERS label-silver shell-gold shell (Au@label@Ag@Au NPs), functionalized on the outer Au surface by MC-LR and/or MC-RR aptamers. These NPs are immobilized on asymmetric Au nanoflowers (AuNFs) dispersed on planar silicon substrates through DNA hybridization of the aptamers and capture DNA sequences with which the AuNFs are functionalized, thereby forming core-satellite nanostructures on the substrates. This construction led to greater electromagnetic (EM) field enhancement of the Raman label-modified region, as supported by finite-difference time-domain (FDTD) simulations of the core-satellite assembly. In the presence of MC-LR and/or MC-RR, the aptamer-functionalized NPs dissociate from the AuNFs because of the stronger affinity of the aptamers with the MCs, which decreases the SERS signal, thus allowing indirect detection of the MCs. The improved SERS sensitivity significantly decreased the limit of detection (LOD) for separate MC-LR detection (0.8 pM) and for multiplex detection (1.5 pM for MC-LR and 1.3 pM for MC-RR), compared with other recently reported SERS-based methods for MC-LR detection. The aptasensors show excellent selectivity to MC-LR/MC-RR and excellent recoveries (96-105%). The use of these SERS aptasensors to monitor MC-LR production over 1 week in a culture medium of M. aeruginosa cells demonstrates the applicability of the sensors in a realistic environment. |
| Databáze: | OpenAIRE |
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