A novel and convenient near-infrared fluorescence “turn off–on” nanosensor for detection of glucose and fluoride anions

•A novel and convenient fluorescence nanosensor for detection of glucose and fluoride anions was established.•The method was based on the fluorescence “turn off–on” of 3-aminobenzeneboronic acid functionalized CuInS2 QDs.•Good sensitivity and selectivity were obtained.•Glucose and fluoride anions in real sample was detected with satisfactory results.

In this paper, 3-aminobenzeneboronic acid functionalized CuInS2 quantum dots (APBA-CuInS2 QDs) were prepared and utilized as a near-infrared fluorescence nanosensor for the detection of glucose and fluoride anions. The APBA-CuInS2 QDs had a symmetric fluorescence emission centered at 742 nm that was in the near-infrared spectral region. The APBA functional groups, which were reactive toward vicinal diols, could covalently bridge the glucose molecule and induced the initial dispersed APBA-CuInS2 QDs aggregate to form a large assembly, leading to the fluorescence of APBA-CuInS2 QDs turned off via the surface quenching states induced mechanism. When fluoride anions were added into the APBA-CuInS2 QDs/glucose system, the assembly was destroyed and as a result the quenched fluorescence dramatically turned on. The proposed nanosensor could be used for glucose detection in the concentration range of 0.005–8 mmol L−1 with a detection limit of 1.2 μmol L−1. The linear range for fluoride anions was 0.1–700 μmol L−1 with a detection limit of 0.029 μmol L−1. Furthermore, the feasibility of the proposed nanosensor in real samples assay was also studied and satisfactory results were obtained.