CdTe quantum dots as a highly selective probe for prion protein detection: Colorimetric qualitative, semi-quantitative and quantitative detection

CdTe quantum dots (QDs) were used as a highly selective probe for the detection of prion protein. Orange-emitting precipitates appeared within 30 s of the addition of recombination prion protein (rPrP) to a solution of green-emitting CdTe QDs. This allowed colorimetric qualitative and semi-quantitative detection of rPrP. The decrease in fluorescence intensity of the supernatant could be used for quantitative detection of rPrP. The fluorescence intensity of the supernatant was inversely proportional to the rPrP concentration from 8 to 200 nmol L−1 (R2 = 0.9897). Transmission electron microscopy results showed that fibrils existed in the precipitates and these were partly transformed to amyloid plaques after the addition of rPrP.