Interactions of proteins with metal-based nanoparticles from a point of view of analytical chemistry - Challenges and opportunities

Interactions of proteins with nanomaterials draw attention of many research groups interested in fundamental phenomena. However, alongside with valuable information regarding physicochemical aspects of such processes and their mechanisms, they more and more often prove to be useful from a point of view of bioanalytics. Deliberate use of processes based on adsorption of proteins on nanoparticles (or vice versa) allows for a development of new analytical methods and improvement of the existing ones. It also leads to obtaining of nanoparticles of desired properties and functionalities, which can be used as elements of analytical tools for various applications. Due to interactions with nanoparticles, proteins can also gain new functionalities or lose their interfering potential, which from perspective of bioanalytics seems to be very inviting and attractive. In the framework of this article we will discuss the bioanalytical potential of interactions of proteins with a chosen group of nanoparticles, and implementation of so driven processes for biosensing. Moreover, we will show both positive and negative (opportunities and challenges) aspects resulting from the presence of proteins in media/samples containing metal-based nanoparticles or their precursors.

Array-based "Chemical Nose" Sensing in Diagnostics and Drug Discovery

Array-based sensor "chemical nose/tongue" platforms are inspired by the mammalian olfactory system. Multiple sensor elements in these devices selectively interact with target analytes, producing a distinct pattern of response and enabling analyte identification. This approach offers unique opportunities relative to "traditional" highly specific sensor elements such as antibodies. Array-based sensors excel at distinguishing small changes in complex mixtures, and this capability is being leveraged for chemical biology studies and clinical pathology, enabled by a diverse toolkit of new molecular, bioconjugate and nanomaterial technologies. Innovation in the design and analysis of arrays provides a robust set of tools for advancing biomedical goals, including precision medicine.

Light-induced self-assembly of bi-color CdTe quantum dots allows the discrimination of multiple proteins

We have found that the addition of proteins can greatly influence the light-induced self-assembly (LISA) behavior of bi-color thioglycolic acid (TGA)-capped CdTe Quantum Dots (QDs) and thus cause significant changes of their fluorescence (FL) signals (color and intensity), according to which a dual-channel FL sensor can be established for simultaneous discrimination of multiple proteins. The sensor is successfully used for the identification of ten native proteins and ten thermally denatured proteins and eight native proteins artificially added in human urine, respectively, during which process principal component analysis (PCA) is utilized to differentiate the targets based on their corresponding FL change patterns. This assay has provided a visual and simple method for the discrimination of various analytes, which may have great potential in the study of conformational changes of biomacromolecules and the analysis of real biological fluids.

Synthesis of Gold Nanoparticles from Au(I) Ions That Shuttle To Solidify: Application on the Sensor Array Design

Metal-mediated interlocking rings won the 2016 Nobel Prize in Chemistry. The metal-directed interlocking rings in macromolecular systems (e.g., proteins) may be similar to the form of Maxwell's electromagnetic waves; the metal ions may shuttle among the rings in the special environment. To verify this hypothesis, we designed a general approach to synthesize the multicolored gold nanoparticles (GNPs) mediated by Au(I)-directed interlocking rings in proteins. The Au(I) ions shuttled among these interlocking rings in the strong alkaline solution. Through the rapid nucleation method, the multicolored GNPs of different morphology and sizes were synthesized in the multiple honeycombed templates. On the basis of the "three-color" principle of Thomas Young, we extracted the red, green, and blue (RGB) alterations of GNPs to fabricate a visual sensor array for protein discrimination. The fingerprints (ΔRGB) were obtained from the target proteins and fed into computer programs. The proposed sensing platform was also applied to detect lysozyme in human tears with satisfactory results. Importantly, we forecasted that lysozyme could be the effective drug for curing dacryocystitis and nasolacrimal duct obstruction diseases.

A multicoloured Au NCs based cross-reactive sensor array for discrimination of multiple proteins

An easily accessible and potentially powerful effective cross-reactive sensor array based on six kinds of fluorescent Au NCs for discriminating multiple proteins according to the diverse fluorescence intensity response patterns was developed.