In situ fabrication of label-free optical sensing paper strips for the rapid surface-enhanced Raman scattering (SERS) detection of brassinosteroids in plant tissues

Publication date: 1 April 2017
Source:Talanta, Volume 165
Author(s): Miao Chen, Zhimin Zhang, Minzhuo Liu, Chen Qiu, Hua Yang, Xiaoqing Chen
A surface-enhanced Raman scattering (SERS)-functionalized, gold nanoparticle (AuNPs)-immobilized paper strip was developed to realize label-free rapid detection of brassinosteroids (BRs) in plant tissues. The AuNPs paper strip was fabricated through utilizing poly(γ-glutamic acid) (γ-PGA) as the linker and concentrator for the directly immobilized AuNPs on paper, which can circumvent many drawbacks of the existing SERS substrates. An enhancement factor of 1.13×10⁸, high reproducibility (relative standard deviation of 4.78%), highly sensitive detection limit with a correlation coefficient of 0.99 (1×10^–11M 4-mercaptophenylboronic acid), and long-term stability for the responses of the SERS-functionalized AuNPs paper strip to Raman intensities were achieved by optimizing reaction conditions including the concentrations of γ-PGA and HAuCl4/NaBH4. Ultimately, this developed paper strip was applied to the determination of BRs in plant tissues, obtaining precisions with RSD values in a range of 3.0–13.8%. The SERS-functionalized AuNPs paper strip featuring label-free rapid analysis, and high sensitivity could serve as an excellent alternative for on-site rapid detections.

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