Reliable detection of malachite green by self-assembled SERS substrates based on gold–silicon heterogeneous nano pineapple structures

• Published in: Food chemistry Vol. 451; p. 139454
• Main Authors: Liu, Yu-ning, Li, Jian-jun, Weng, Guo-jun, Zhu, Jian, Zhao, Jun-wu
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2024
• Subjects: Asymmetric branched nanoparticles; Malachite green; Self-assembled SERS substrate; Surface-enhanced Raman scattering; Asymmetric branched nanoparticles; Surface-enhanced Raman scattering; Self-assembled SERS substrate; Malachite green
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139454

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•A heterodimer of SiO2 and Au with asymmetric gold branches and nanopineapple structure were synthesized.•Nano pineapple structures showed better SERS properties than symmetric branch structure.•Nanopineapple’s asymmetric compositions enabled the formation of self-assembled membrane with uniform branch orientation.•The self-assembled substrate showed good SERS properties with EF of 1.1×106 and homogeneity with RSD of 3.1 %.•A SERS sensor was constructed for the sensitive and reliable detection of malachite green.
Morphology regulation of heterodimer nanoparticles and the use of their asymmetric features for further practical applications are crucial because of the rich optical properties and various combinations of heterodimers. This work used silicon to asymmetrically wrap half of a gold sphere and grew gold branches on the bare gold surface to form heterogeneous nano pineapples (NPPs) which can effectively improve Surface-enhanced Raman scattering (SERS) properties through chemical enhancement and lightning-rod effect respectively. The asymmetric structures of NPPs enabled them to self-assemble into the monolayer membrane with consistent branch orientation. The prepared substrate had high homogeneity and better SERS ability than disorganized substrates, and achieved reliable detection of malachite green (MG) in clams with a detection limit of 7.8 × 10−11 M. This work provided a guide to further revise the morphology of heterodimers and a new idea for the use of asymmetric dimers for practically photochemical and biomedical sensing.