Improved charge-transfer enhancement by codoping Mg/Zn into ZrO2 for quinolone antibiotic drug determination

Noble metal-based surface-enhanced Raman scattering (SERS)-active substrates have been developed for decades. However, nonreproducible aggregation and photoinduced molecular degradation limit the development of SERS technology. To overcome the shortcomings of noble metal-based SERS substrates, we designed ZrO 2 -based nanoparticles (NPs). By doping Mg and/or Zn ions into these ZrO 2 NPs , the SERS activity was significantly improved. Mg/Zn codoping of ZrO 2 resulted in a much higher oxygen deficiency, thereby providing a sufficient surface state energy (Ess) level to enable charge transfer (CT). The primary contribution for the Mg/Zn-codoped ZrO 2 was determined to be from the CT resonance effect, resulting in an enhancement factor (EF) as high as 10 4 . Most importantly, the CT-induced enhancement of Raman scattering based on Mg/Zn-codoped ZrO 2 has already demonstrated some promising applications in highly sensitive quinolone antibiotic drug determination. Different kinds of quinolone antibiotic drugs can be easily identified and quantitatively analyzed with high sensitivity and reproducibility.