Magneto-electrochemical biosensing for pathogen detection using nuclease-responsive nanohybrids


Kibar G., KAVRUK M., Hernandez F. J., Borsa B. A., Dursun A. D., Ozalp V. C.

Microchimica Acta, vol.193, no.5, 2026 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 193 Issue: 5
  • Publication Date: 2026
  • Doi Number: 10.1007/s00604-026-08087-3
  • Journal Name: Microchimica Acta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex
  • Keywords: Electrochemical biosensor, Emulsion polymerization, Green synthesis, Nuclease-based detection, POSS, Streptococcus pneumoniae, Superparamagnetic iron oxide nanoparticles, UV-polymerization
  • Istanbul University-Cerrahpasa Affiliated: Yes

Abstract

The development of sustainable and highly sensitive diagnostic platforms is critical for rapid pathogen identification and effective disease management. Here, a green, magneto-electrochemical biosensing strategy is reported for the selective detection of Streptococcus pneumoniae based on pathogen-specific nuclease activity. Uniform organic–inorganic hybrid polyhedral oligomeric silsesquioxane (POSS) nanoparticles were synthesized via an ultrafast UV-initiated emulsion polymerization within 5 min using an eco-friendly approach. The nanoparticles were sequentially functionalized by in situ deposition of superparamagnetic iron oxide nanoparticles and biomimetic polydopamine coating, enabling robust and high-density immobilization of nuclease-responsive oligonucleotide probes. The resulting PDA@SPION/POSS nanohybrids exhibit controlled size, preserved structural integrity, and strong superparamagnetic behavior, allowing efficient magnetic manipulation and electrochemical signal transduction. Upon exposure to S. pneumoniae, nuclease-mediated probe cleavage produces a pronounced electrochemical response, enabling label-free detection over a wide dynamic range (102–10⁸ CFU mL⁻¹) with a detection limit of 102 CFU mL⁻¹. High selectivity against non-target bacteria highlights the specificity of the enzymatic recognition mechanism. This work establishes a sustainable and amplification-free biosensing platform with strong potential for rapid clinical diagnostics.