Fluorescence probe for sensitive and selective screening of kanamycin using Co2+ ions quenched gold nanoclusters

Spectrochim Acta A Mol Biomol Spectrosc. 2026 Jun 5:354:127657. doi: 10.1016/j.saa.2026.127657. Epub 2026 Feb 26.

Abstract

The turn "off-on" fluorescence (FL) probe was developed for screening of kanamycin (KAN) in food and beverages in the present work. Due to dynamic quenching, the FL signal of glutathione protected gold nanoclusters (GSH-AuNCs) was quenched by using cobalt (Co2+) ions. GSH-AuNCs acted as "turn-off" due to Co2+ ions. The FL intensity quenched by Co2+ ions was regained using KAN due to KAN triggered aggregation induced enhancement (AIEE) of GSH-AuNCs, and GSH-AuNCs-Co2+ acted as a "turn-on" probe. The probe GSH-AuNCs-Co2+ was used for KAN screening for the first time, and it has an extended linear range of 1-30 μM with a detection limit of 0.5 μM. The probe successfully detected KAN in NFC mango juice, yoghurt, and tomatoes with a good 92.73-108.45% recovery range. The wide detection platform with improved sensitivity and real-world utilization for screening KAN was established by the current work.

Keywords: Cobalt ions; Food screening; Gold nanoclusters; Kanamycin; Off–on.

MeSH terms

  • Cobalt* / chemistry
  • Fluorescent Dyes* / chemistry
  • Food Analysis / methods
  • Fruit and Vegetable Juices / analysis
  • Glutathione / chemistry
  • Gold* / chemistry
  • Kanamycin* / analysis
  • Limit of Detection
  • Metal Nanoparticles* / chemistry
  • Spectrometry, Fluorescence / methods

Substances

  • Gold
  • Cobalt
  • Kanamycin
  • Fluorescent Dyes
  • Glutathione