Abstract
A nanostructure of self-assembly silver nanoparticles decorated on gold nanoislands (SAM Ag@AuNIs) is proposed in this article as a sensitive sensing medium for localized surface plasmon resonance (LSPR) biosensing applications. A wide tunable plasmonic sensing range from 472 to 552 nm is found by adjusting the Au–Ag atomic ratio. Biotin is employed as an indicator to investigate the potential biosensing applicability and site-specific bioactivity of the SAM Ag@AuNIs. In virtue of a white light common-path sensing system, direct adsorption of biotin on the SAM Ag@AuNIs is measured in label-free manner with detection limit (LOD) of 2.9 pg mL−1 (11.87 × 10−12 m). It is 105-fold better than that of TiN film, which is previously reported to provide excellent LSPR LOD after functionalization with biotin. The experimental and computational results indicate that the biotin molecule can selectively immobilize onto the Ag nanoparticles (AgNPs) surface through S–Ag bonding, resulting in site-specific functionalization. Meanwhile, the geometry of AgNPs/AuNIs provided a coupling effect that helps to improve the sensitivity. Here, AgNPs are, for the first time, reported to be directly functionalized with biotin. The SAM Ag@AuNIs can serve as a desirable plasmonic medium in the biosensing community based on the exceptionally good LOD of biotin.
| Original language | English |
|---|---|
| Article number | 2200339 |
| Number of pages | 12 |
| Journal | Advanced Materials Interfaces |
| Volume | 9 |
| Issue number | 15 |
| Online published | 10 Apr 2022 |
| DOIs | |
| Publication status | Published - 23 May 2022 |
Research Keywords
- biosensors
- biotin
- density functional theory
- finite difference time domain
- site-specific functionalization
- localized surface plasmon resonance
Publisher's Copyright Statement
- COPYRIGHT TERMS OF DEPOSITED POSTPRINT FILE: This is the peer reviewed version of the following article: Liu, L., Liang, X., Qiu, G., Guo, C., Chan, Y. K., & Wu, C-M. L. (2022). Self-Assembly Silver Nanoparticles Decorated on Gold Nanoislands for Label-Free Localized Surface Plasmon Resonance Biosensing. Advanced Materials Interfaces, 9(15), Article 2200339, which has been published in final form at https://doi.org/10.1002/admi.202200339.
- This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.