Magnetic imprinted surface enhanced Raman scattering (MI-SERS) based ultrasensitive detection of ciprofloxacin from a mixed sample

Abstract

A new method for fast extraction and ultra-sensitive detection of ciprofloxacin based on magnetic imprinted surface-enhanced Raman scattering (MI-SERS) has been developed in this paper. This method is a combination of three techniques, which are a magnetic separation technique, a molecular imprinting technique and a surface-enhanced Raman scattering technique. We designed and fabricated core–shell structured magnetic molecularly imprinted polymers (MIPs) which can be applied to specifically recognise ciprofloxacin and extract it from a mixed system. The whole extraction and clean-up procedures are assisted by a magnetic field, which makes it much easier than traditional centrifugal separation. In addition to this, surface-enhanced Raman scattering (SERS) was applied as the detection tool, which makes the detection limit for ciprofloxacin by this method as low as 10⁻⁹ mol L⁻¹. Furthermore, we integrated these core–shelled magnetic-MIPs on a magnet chip and detected ciprofloxacin from fetal bovine serum. The whole detection process can be finished within ten minutes and the limit of detection by this chip can reach 10⁻⁷ mol L⁻¹.