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

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(mu M) 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.

Automated summary

This study proposes an optical fiber SPR biosensor based on a sandwich model with gold nanoparticles amplification for high sensitivity DNA hybridization detection. The experimental results show a log-linear response in the DNA concentration range of 1 pM-10 nM with high sensitivity and detection limit.