Targeted-activation superparamagnetic spherical nucleic acid nanomachine for ultrasensitive SERS detection of lysozyme based on a bienzymatic-mediated in situ amplification strategy

Anal Sci. 2024 Mar;40(3):429-438. doi: 10.1007/s44211-023-00471-w. Epub 2023 Dec 19.

Abstract

Lysozyme (LYS) is a widely used bacteriostatic enzyme. In this paper, we built a sensitive and accurate Raman biosensing platform to detect trace amounts of LYS. The method is based on magnetic spherical nucleic acid formed by a combination of LYS aptamer (Apt) and magnetic beads (MBs). Meanwhile, this method utilizes a dual enzyme-assisted nucleic acid amplification circuit and surface-enhanced Raman scattering (SERS). In this sensing strategy, which is based on the specific recognition of Apt, magnetic spherical nucleic acids were associated with SERS through a nucleic acid amplification circuit, and the low abundance of LYS was converted into a high-specificity Raman signal. Satellite-like MB@AuNPs were formed in the presence of the target, which separated specifically in a magnetic field, effectively avoided the interference of complex sample environment. Under the optimal sensing conditions, the concentration of LYS exhibited a good linear relationship between 1.0 × 10-14 and 5.0 × 10-12 M and the limit of detection was as low as 8.3 × 10-15 M. In addition, the sensor strategy shows excellent accuracy and sensitivity in complex samples, providing a new strategy for the specific detection of LYS.

Keywords: Bienzymatic-mediated; LYS; MB@AuNPs; SERS.

MeSH terms

  • Biosensing Techniques* / methods
  • Gold
  • Limit of Detection
  • Magnetic Iron Oxide Nanoparticles
  • Metal Nanoparticles*
  • Muramidase
  • Nucleic Acids*
  • Spectrum Analysis, Raman / methods

Substances

  • Nucleic Acids
  • Muramidase
  • Gold