Colorimetric sensing strategy for multiplexed detection of proteins based on three DNA-gold nanoparticle conjugates sensors

Proteins play important roles in mediating various forms of life activities. The development of convenient and reliable strategies for simultaneous recognition of multiple proteins is meaningful for early diagnostics of diseases. Herein, we develop a differential colorimetric sensor array, which is made of nonspecific single-stranded DNA (ssDNA) as receptors and gold nanoparticles (AuNPs) as colorimetric probes for multiple identification of the nine proteins. Upon the addition of analyte proteins, different interactions between various proteins and ssDNA lead to the desorption of different amounts of ssDNA from the AuNP surface, thus resulting in AuNP aggregation to varying degrees in salt environment, which in turn leads to the colorimetric signal change of AuNPs. On the basis of the principle, nine proteins (i.e., bovine serum albumin (BSA), horseradish peroxidase (HRP), pepsin (Pep), hemoglobin (Hem), egg white albumin (EA), trypsin (Try), myoglobin (Myo), cytochrome C (Cyt-C), and concanavalin (Con)) at low concentration (20 nM) were well discriminated by the sensor array.

Automated summary

A differential colorimetric sensor array was developed for the simultaneous and accurate identification of nine proteins, showing promising potential for early disease diagnostics.