Fluorescence sensing of chloramphenicol based on oxidized single-walled carbon nanohorn/silicon quantum dots- aptamers

Based on the fluorescence properties of silicon quantum dots-aptamers (SiQDs-aptamers) and the excellent quenching ability of oxidized single-walled carbon nanohorns (oxSWCNHs), a simple, fast, and efficient fluorescence-on method for the determination of chloramphenicol (CAP) was established. Single-walled carbon nanohorns (SWCNHs) are linked with carboxyl groups to generate oxSWCNHs with good dispersibility, which are added to specific SiQDs-aptamers at optimal concentrations to constitute on-off oxSWCNHs / SiQDs-aptamers fluorescence sensor. In this study, the structure of oxSWCNHs was verified, and their comprehensive properties were characterized. Finally, the detection of CAP with oxSWCNHs as a quencher was realized. Under these states, the limit of detection (LOD) of CAP was 0.6 ng/mL (3σ/S, n = 11), the recovery rate in different actual samples was 94.1%∼108.1%, and the relative standard deviation (RSD) did not exceed 6.1%, which can be accurately used for determination of CAP in milk samples.