SERS investigation and detection of levofloxacin drug molecules on semiconductor TiO2: Charge transfer contribution

•TiO2 and Zn doped TiO2 nanoparticles were synthesized and served as SERS-active substrate for the detection of levofloxacin (LVFX) drug molecules.•Both experimental and theoretical methods are used to study the enhanced mechanism and interaction between substrate and drug molecule.•The detection limit (S/N=3) of LVFX can be reduced to 1.29×10−7mol/L by this method.•There is a good linear relationship in the range of 1×10−3–1×10−7mol/L concentration for SERS of LVFX on TiO2.