Multidimensional Sensor for Pattern Recognition of Proteins Based on DNA-Gold Nanoparticles Conjugates

We presented an extensible multidimensional sensor with conjugated nonspecific dye-labeled DNA sequences absorbed onto gold nanoparticles (DNA-AuNPs) as receptors. At the presence of target protein, DNA was removed from the surface of AtiNP's due to the competitive binding, which resulted in a red-to-blue color change along with salt-induced aggregation of AuNPs for colorimetric analysis and fluorescent "turn-on" signal of the labeled dye for fluorescence analysis. The orthogonal and complementary fluorescent and colorimetrid signals obtained from each protein were applied to distinguish different proteins. By simply changing the DNA sequences, more dital-channel sensing elements could be easily obtained and added into this multidimensional sensor. This enhanced, its, discriminating, power to the proteins. With three sensing elements, our extensible multidimensional sensing platform exhibited excellent discrimination ability. Eleven proteins at the concentration of 50 nM had been classified with accuracies of 100% by using linear discriminant analysis (LDA). Remarkably, two similar proteinS [bovine serum albumin (BSA) and human serum albumin (HSA)] at various concentrations arid the mixture of these two proteins, with different molar, ratios had been successfully discriminated in one LDA plot as well Furthermore, in the presence of human urine sample, 10 proteins at 1.0 mu M could also be well-discriminated The accuracy of distrimination of unknown Samples was all 100% for these experiments. This strategy is a complement of the multidimensional sensing, system and traditional sensor platform, offering a new way to develop sensitive array sensing systems.