Fluorescent silica nanoparticles as nano-chemosensors for the sequential detection of Pb2+ ions and bacterial-spore biomarker dipicolinic acid (DPA) in aqueous solution

Cetinkaya Y. N., Bulut O., ÖKTEM H. A., Yilmaz M. D.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, vol.303, 2023 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 303
  • Publication Date: 2023
  • Doi Number: 10.1016/j.saa.2023.123222
  • Journal Name: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, Chemical Abstracts Core, Chimica, Compendex, INSPEC, MEDLINE, Veterinary Science Database
  • Keywords: Bacterial spores, Dipicolinic acid, Fluorescence, Lateral flow, Pb2+, Silica nanoparticles
  • Middle East Technical University Affiliated: Yes


Herein, we report fluorescein-labelled silica nanoparticles (FSNP) which serve as fluorescent nano-chemosensors for sequential detection of Pb2+ (which is a toxic heavy metal) and dipicolinic acid (DPA) (which is a distinctive indicator biomarker of bacterial spores) with high sensitivity and selectivity. The fluorescence of FSNP is quenched because of the complex formation between Pb2+ ions and surface amide groups, however, the fluorescence is recovered in contact with DPA, resulting from the association of DPA with surface bound Pb2+ ions. FSNP-Pb2+ complexes show high sensitivity towards DPA with a low detection limit of 850 nM which is approximately seventy times lower than the infectious dosage of bacterial spores (60 μM). Lateral flow test platform was further developed to show the applicability and practicability of our system.