Bovine serum albumin coated CuInS_2 quantum dots as a near-infrared fluorescence probe for 2,4,6-trinitrophenol detection

摘要

In this paper, a novel near-infrared fluorescence probe for the determination of 2,4,6-trinitrophenol (TNP) was developed based on bovine serum albumin (BSA) coated CuInS_2 quantum dot (QD). Water-soluble CuInS_2 QDs were directly synthesized in aqueous solution with mercaptopropionic acid (MPA) as stablizers, and it was coated by BSA via an amide link interacting with carboxyl of the MPA-capped CuInS_2 QDs. The obtained BSA coated CuInS_2 QDs (BSA-CuInS_2 QDs) can bind TNP in water via the acid-base pairing interaction between electron-rich amino groups of BSA and electron-deficient nitroaromatic rings, and leading the fluorescence quenching of BSA-CuInS_2 QDs. The quenched fluorescence intensity of BSA-CuInS_2 QDs was proportional to the concentration of TNP in the concentration ranges from 50 nmol/L to 3.0 μmol/L. The detection limit (LOD) for TNP was 28 nmol/L. The developed fluorescence probe showed a excellent resistant to interference of metal ions such as K~+, Na ~+, Zn~(2+), Cu~(2+), Hg~(2+), and Pb ~(2+). The developed biosensor was applied to the determination of TNP in spiked water samples with satisfactory results.