Chiral Recognition on Bare Gold Surfaces by Quartz Crystal Microbalance

Abstract

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However,t he organic sensitive layer may easily cause dissipation of oscillation or detachmentand weaken the signal transfer during the molecular recognition processes.I nt his work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids,r elatively higher selectivity of D-enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations,wedemonstrate that the chiral nature of Au surface playsanimportant role in the selective binding of specific D-amino acids.These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.

Controlling Adsorption of Diblock Copolymer Nanoparticles onto an Aldehyde-Functionalized Hydrophilic Polymer Brush via pH Modulation

“…62 Herein we employ QCM to quantify the adsorption of PGMA 51 −PBzMA y nanoparticles (y = 200, 400, or 800) onto PAGEO5MA brushes by determining the adsorbed mass per unit area (Γ, mg m −2 ). 84,85 With QCM, we first demonstrate that the aldehyde groups within the hydrophilic brush chains are essential for strong nanoparticle adsorption. PGEO5MA and PAGEO5MA brushes were grown from separate QCM sensors before being exposed in turn to the same 1.0% w/w dispersion of PGMA 51 −PBzMA 800 nanoparticles at pH 4.…”

“…QCM is widely used for the construction of various types of biosensors − and can also be used to characterize the viscoelastic properties of thin polymer films such as polymer brushes. − We have recently employed QCM to quantify the extent of adsorption of either diblock copolymer nanoparticles or nanosized oil droplets onto model soft substrates ,, and for the conjugation of a globular protein to a PAGEO5MA brush via Schiff base chemistry . Herein we employ QCM to quantify the adsorption of PGMA 51 –PBzMA y nanoparticles ( y = 200, 400, or 800) onto PAGEO5MA brushes by determining the adsorbed mass per unit area (Γ, mg m –2 ). , …”

“… 62 Herein we employ QCM to quantify the adsorption of PGMA 51 –PBzMA y nanoparticles ( y = 200, 400, or 800) onto PAGEO5MA brushes by determining the adsorbed mass per unit area (Γ, mg m –2 ). 84 , 85 …”

Design of surface nanostructures for chirality sensing based on quartz crystal microbalance

“…Bare metal layers were very rarely used for chiral recognition directly in the QCM system. Ji and Liu et al studied for the first time the chiral adsorption behavior of bare gold electrodes for amino acids by QCM ( Figure 11 ) [ 144 ]. The Au surfaces contain 27–37% of chiral surfaces and the most exposed surface of Au(324).…”

Chiral molecular imprinting-based SERS detection strategy for absolute enantiomeric discrimination

“…The photothermal heat aggravates the instability of the Raman optical activity signal, changes in dielectric properties of the nanoparticles, and even destroys the conformation of chiral molecules 8 , 9 . The other systems rely on chiral selectors, such as cyclodextrins 10 , metal surfaces with localized asymmetric sites 11 , covalent organic frameworks 12 , polymeric materials 13 , and chiral imprinted surfaces 14 . Host–guest interaction is the dominant mechanism of chiral discrimination in most such systems.…”