Optical fiber SPR biosensor based on gold nanoparticle amplification for DNA hybridization detection

• Published in: Talanta (Oxford) 2022-09, Vol.247, p.123599-123599, Article 123599
• Main Authors: Li, Like, Zhang, Ya-nan, Zheng, Wanlu, Li, Xuegang, Zhao, Yong
• Format: Article
• Language: English
• Subjects: Biosensor; DNA hybridization; Gold nanoparticles; Optical fiber sensor; Surface plasmon resonance
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123599

An optical fiber SPR biosensor based on multimode fiber (MMF)- hollow core fiber (HCF)-MMF is proposed and experimentally confirmed for in situ DNA hybridization analysis. In order to improve the sensitivity of DNA hybridization detection, a sandwich model based on gold nanoparticles (AuNPs) amplification is proposed. In this model, the probe DNA (pDNA) is first modified on the optical fiber sensing area by covalent bonding, and then the biotinylated target DNA (tDNA) is modified on the AuNPs by the high affinity between biotin and streptavidin. Finally, the tDNA on the surface of the AuNPs specifically hybridizes with the pDNA on the optical fiber to form a sandwich model. The near field coupling enhancement between AuNPs and gold film and the high mass ratio of AuNPs give high sensitivity to DNA hybridization detection. Experimental results show that the sandwich-type fiber SPR sensor has a log-linear response in the DNA concentration range of 1 pM–10 nM, and the sensitivity and detection limit are 4.04 nm/log(μM) and 1pM, respectively. This is 1.44 times more sensitive than that without sandwich assay. In addition, the DNA sensor has good specificity and stability, which foreshadows its great application potential in the fields of disease diagnosis, microbial detection and environmental science. [Display omitted] •An optical fiber SPR biosensor was proposed for in situ DNA hybridization analysis.•A sandwich model based on AuNPs amplification improved the sensitivity of DNA hybridization detection by about 1.44 times.•Wide detection range from 1 pM to 10 nM was realized.•The minimum detectable concentration of the sensor was as low as 1 pM.