Experimental Evaluation of Quantum Dots and Antibodies Conjugation by Surface Plasmon Resonance Spectroscopy

Nano-bio convergence unveiled: Systematic review on quantum dots-protein interaction, their implications, and applications

Quantum dots (QDs) are semiconductor nanocrystals (2-10 nm) with unique optical and electronic properties due to quantum confinement effects. They offer high photostability, narrow emission spectra, broad absorption spectrum, and high quantum yields, making them versatile in various applications. Due to their highly reactive surfaces, QDs can conjugate with biomolecules while being used, produced, or unintentionally released into the environment. This systematic review delves into intricate relationship between QDs and proteins, examining their interactions that influence their physicochemical properties, enzymatic activity, ligand binding affinity, and stability. The research utilized electronic databases like PubMed, WOS, and Proquest, along with manual reviews from 2013 to 2023 using relevant keywords, to identify suitable literature. After screening titles and abstracts, only articles meeting inclusion criteria were selected for full text readings. This systematic review of 395 articles identifies 125 articles meeting the inclusion criteria, categorized into five overarching themes, encompassing various mechanisms of QDs and proteins interactions, including adsorption to covalent binding, contingent on physicochemical properties of QDs. Through a meticulous analysis of existing literature, it unravels intricate nature of interaction, significant influence on nanomaterials and biological entities, and potential for synergistic applications harnessing both specific and nonspecific interactions across various fields.

Surface-Plasmon-Resonance Amplification of FMD Detection through Dendrimer Conjugation

The amplification of the surface plasmon resonance (SPR) sensitivity for the foot-and-mouth disease (FMD) detection was studied using Poly(amidoamine) (PAMAM) succinamic-acid dendrimers. The dendrimers were conjugated with the complementary annealed with the aptamers capable of binding specifically to FMD peptides. The tethered layer of the dendrimer-conjugated double-stranded(ds)-aptamers was formed on the SPR sensor Au surface via a thiol bond between the aptamers and Au. After the tethered layer was formed, the surface was taken out of the SPR equipment. Then, the ds-aptamers on the surface were denatured to collect the dendrimer-conjugated single-stranded(ss)-complementary. The surface with only the remaining ss-aptamers was transferred again to the equipment. Two types of the injections, the FMD peptide only and the dendrimer-conjugated ss-complementary followed by the FMD peptides, were performed on the surface. The sensitivity was increased 20 times with the conjugation of the dendrimers, but the binding rate of the peptides became more than two times slower.

Thermodynamic Characterization of the Interaction of Biofunctionalized Gold Nanoclusters with Serum Albumin Using Two- and Three-Dimensional Methods

Fluorescent gold nanoclusters have been successfully used as fluorescent markers for imaging of cells and tissues, and their potential role in drug delivery monitoring is coming to the fore. In addition, the development of biosensors using structure-tunable fluorescent nanoclusters is also a prominent research field. In the case of these sensor applications, the typical goal is the selective identification of, e.g., metal ions, small molecules having neuroactive or antioxidant effects, or proteins. During these application-oriented developments, in general, there is not enough time to systematically examine the interaction between nanoclusters and relevant biomolecules/proteins from a thermodynamic viewpoint. In this way, the primary motivation of this article is to carry out a series of tests to partially fill this scientific gap. Besides the well-known fluorescent probes, the mentioned interactions were investigated using such unique measurement methods as surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). These two-dimensional (at the solid/liquid interface) and three-dimensional (in the bulk phase) measuring techniques provide a unique opportunity for the thermodynamic characterization of the interaction between different gold nanoclusters containing various surface functionalizing ligands and bovine serum albumin (BSA).

Recent Advances in Synthesis and Application of Metal Oxide Nanostructures in Chemical Sensors and Biosensors

Nanostructured materials formed from metal oxides offer a number of advantages, such as large surface area, improved mechanical and other physical properties, as well as adjustable electronic properties that are important in the development and application of chemical sensors and biosensor design. Nanostructures are classified using the dimensions of the nanostructure itself and their components. In this review, various types of nanostructures classified as 0D, 1D, 2D, and 3D that were successfully applied in chemical sensors and biosensors, and formed from metal oxides using different synthesis methods, are discussed. In particular, significant attention is paid to detailed analysis and future prospects of the synthesis methods of metal oxide nanostructures and their integration in chemical sensors and biosensor design.