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

Abstract

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 AuNPs 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 colorimetric signals obtained from each protein were applied to distinguish different proteins. By simply changing the DNA sequences, more dual-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 and 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 μM could also be well-discriminated. The accuracy of discrimination 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.

Suspension Array of Ionic Liquid or Ionic Liquid–Quantum Dots Conjugates for the Discrimination of Proteins and Bacteria

“…It is known that the very complex matrixes in human urine is highly challenging for the identification of proteins and other biological targets. 25 However, in the present case, each of the relevant proteins involved in the urine sample matrix generated a distinct response, and a 100% identification accuracy is achieved for all the 6 proteins. This observation indicated that the sensing array system based on QDs/IL-QDs conjugates offers promising potential for the discrimination of proteins in real biological samples.…”

Multidimensional colorimetric sensor array for discrimination of proteins

“…The sensing system showed various color changes due to different properties of every protein, such as pI, molecular weight. The variation of the color change as fingerprint could be used to discriminate proteins (Sun et al, 2015;Lu et al, 2013aLu et al, , 2013b. The absorption profiles see Fig.…”

“…In the past few years, many kinds of materials, such as organic compounds (Jiménez et al, 2004;Schmittel and Lin, 2007), inorganic compound films (Hu et al, 2011), nanoparticles (Li et al, 2014;Liu et al, 2010;Lu et al, 2013aLu et al, , 2013bRana et al, 2015;Wang et al, 2009), graphene oxide (Lu et al, 2013a(Lu et al, , 2013b and quantum dots (Sang and Wang, 2014;Wu et al, 2011) have been reported as the single transducer with fundamentally different transduction principles for detection of various analytes. Recently, we have proposed an extensible multidimensional sensor array based on DNA-AuNPs conjugates with dual-channel (fluorescence and colorimetric), which could easily increase the number of sensing elements by simply changing the DNA sequences for enhancing discrimination ability of the sensor (Sun et al, 2015). However, in all the previous works, a variety of measure techniques were used to record many signal responses for target analytes against the multidimensional sensors.…”

A Multichannel Pattern-Recognition-Based Protein Sensor with a Fluorophore-Conjugated Single-Stranded DNA Set

“…Thus, fluorophore-conjugated ssDNAs are capable of generating differential optical signals following interactions with different proteins. There are a number of sensing systems that employ complexes of ssDNAs and other materials, such as gold nanoparticles [ 29 , 30 , 31 ], metal oxide nanoparticles [ 32 , 33 ], graphene oxide nanosheets [ 34 , 35 , 36 , 37 , 38 ], and metal oxide nanosheets [ 38 , 39 ].…”