Aptamer-Based Plasmonic Sensor Array for Discrimination of Proteins and Cells with the Naked Eye

Abstract

We developed a colorimetric sensor array with reported protein aptamers as nonspecific receptors. We found that different target proteins could make the aptamer-protected gold nanoparticles (AuNPs) exhibit different aggregation behaviors in the presence of a high concentration salt and cause various color change. On the basis of this phenomenon, we applied a series of reported protein aptamers as a receptor array obtaining a distinct response pattern to each target protein. Seven proteins have been well distinguished with the naked eye at the 50 nM level. Cancerous human cells have also been discriminated from noncancerous cells. This method is simple, label-free, and sensitive. It will broaden the application filed of plasmonic nanoparticle-based sensors and give a new direction of developing sensitive array sensing systems.

Aptamer/AuNP Biosensor for Colorimetric Profiling of Exosomal Proteins

“…[13] Controllable ssDNA (aptamer)/AuNP interaction has previously been explored for protein detection [14] and cancer cell discrimination. [15] In this study, the competitive binding between aptamers and exosomes displaces aptamers from AuNPs, resulting in nanoparticle aggregation. The red-to-blue color change of AuNPs indicates the corresponding binding events between aptamers and exosomal proteins, while the intensity of AuNPs aggregation (A 650 /A 520 ) reflects the relative abundance of target proteins present on the exosome surfaces (Figure 1).…”

Excited Oxidized-Carbon Nanodots Induced by Ozone from Low-Temperature Plasma to Initiate Strong Chemiluminescence for Fast Discrimination of Metal Ions

“…As reported, the cross-reactive signals are crucial important for the fabrication of sensor array. [34][35][36][37][38][39] As resulted, we obtained different CL signals with the presence of different metal ions in C-dots solutions. For example, we recorded the enhanced CL signals with the presence of Zn 2+ , the decreased signals for Fe 3+ , and the almost similar CL signals for Cr 3+ compared with the C-dots solution without any metal ions added ( Figure 6A).…”

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.…”

“…The transducer was constructed by chemically integrating multiple reporter units, such as colorimetric (Color), fluorescence (FL), electrogenerated chemiluminescence (ECL) and electrochemical (EC), which was known as 'lab-on-amolecule' or 'lab-on-a-nanoparticle' (Jiménez et al, 2004;Schmittel and Lin, 2007;Wu et al, 2011). 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).…”