The Study Of Antibiotics Aqueous Solution Using Surface-enhanced Raman Spectroscopy

Since the first antibiotic discovered in1928, antibiotics are widely used in thecontrol of bacterial diseases of humans, livestock and aquatic animals. At the sametime, the antibiotic was found to have a lot of harm to human health and theenvironment. Many antibiotics for humans have toxic reaction, and abuse ofantibiotics lead to drug-resistant. Many countries in the world have introducedpolicies to prohibit or restrict use of antibiotics. But the reality is that abuse ofantibiotics in aquaculture is not disappear despite repeated prohibitions, the detectionof antibiotic residues in culture water is imperative. The antibiotic residue detectionmethods have defects respective, their use is restricted. The standard detection methodcommonly used in China is high-performance liquid chromatography (HPLC) withhigh sensitivity. But the operation of HPLC is a long tedious and time consuming, anddiscomfort for the rapid analysis of a large number of samples and live detection.Surface-enhanced Raman Spectroscopy (SERS) technology, a detection method withthe advantages of rich information, more sensitivity, higher-efficiency, no samplepretreatment and being available in situ, can be applied in detecting single molecule.And it is expected to achieve real-time and rapid detection of antibiotics inaquiculture water.Surface-enhanced Raman spectroscopy was applied to detection of theantibiotics(chloramphenicol, ciprofloxacin, enrofloxacin) which were used inaquaculture despite repeated prohibitions. The silver colloid was prepared bymicrowave method, and the best heat-up time is five minutes. The pH of silver colloidwas changed, the enhancement factor is highest when pH is2. But there is no satisfiedsingle when the antibiotics were detected with silver colloid. The silver colloid filmswere prepared by self-assembly method, and the quartz plates after silanized inAPTMS were immersed in silver colloids with different pH in the process. Theenhancement factor of silver colloid film is best when the pH is4. The steps of silvercolloid film were discussed, and the best step is five. The silver colloid films afterused were rinsed, and the enhancement factor was not significantly lower. The pure aqueous solutions of different concentrations of three antibiotics(chloramphenicol, ciprofloxacin, enrofloxacin) were detected by Microscopes RamanSpectrometer and QE65000spectrometer. The minimum detectable concentrationsmeasured by Microscopes Raman Spectrometer are40ppb、5ppb、40ppbrespectively, which are better than the results of other literatures. And the minimumdetectable concentrations measured by QE65000spectrometer are1ppm、0.1ppm、1ppm. The pure aqueous solutions and seawater solutions of three antibiotics weredetected by QE65000spectrometer, and the minimum detectable concentrations ofseawater solutions are two to ten times of pure aqueous solutions. The enhancementfactor was not significantly lower after immersed in seawater2.5hours, whichdemonstrate the well stability of silver colloid films. The spectra of antibioticssolutions prepared with aquaculture water obtained by QE65000spectrometer. Theinfluence of aquaculture water and fish bait were discussed and the minimumconcentration of chloramphenicol-aquaculture water solutions could be detected is5times of the standard solutions.The silver colloid films have higher sensitivity, repeatability, stability and havehigh application value in detection of antibiotics, which lay a foundation for the real-time and rapid detection of antibiotics in aquiculture water.