Differentiation of proteins and cancer cells using metal oxide and metal nanoparticles-quantum dots sensor array

A novel nanoparticles-quantum dots-based fluorescence sensor array has been developed for sensing proteins and cancer cells. In this study, six types of nanoparticles (NPs, including CuO, ZnO, Eu2O3, AuNPs, AgNPs, Au-Ag core-shell） conjugated with CdSe quantum dots (QDs) were used as sensing elements to create the multi-sensors of array. The fluorescence of quantum dots was efficiently quenched by nanoparticles. Fluorescence turn-on or further quenching could be observed due to the disruption of the nanoparticles-QDs interaction by proteins, affording distinct fluorescence response patterns. Linear discriminant analysis (LDA) was used to analyze the patterns. Moreover, protein quantification could be performed according to the fluorescence intensity on a specific or single sensing element. The linear dynamic ranges of the sensor array for proteins was in the range of 2-50 μM, and the limits of detection (LODs) was below 2 μM that varied for different proteins. Six cancer cells were also successfully differentiated by their fluorescence response patterns. This work indicates that the nanoparticles-QDs-based sensor array has a great potentials to be used in such fields as proteomics and medical diagnostics.