Imparting Biomimetic Ion-Gating Recognition Properties to Electrodes with a Hydrogen-Bonding Structured Core−Shell Nanoparticle Network

Abstract

This paper presents findings of the creation of biomimetic ion-gating properties with core-shell nanoparticle network architectures. The architectures were formed by hydrogen-bonding linkages via an exchange-cross-linking-precipitation reaction pathway using gold nanoparticles capped with thiolate shell and alkylthiols terminated with carboxylic groups as model building blocks. Such network assemblies have open frameworks in which void space is in the form of a channel or chamber with the nanometer-sized cores defining its size, the geometric arrangement defining its shape, and the shell structures defining its chemical specificity. The formation of the network linkages via head-to-head hydrogen-bonded carboxylic terminals and the reversible pH-tuned structural properties between neutral and ionic states were characterized using infrared reflectance spectroscopic technique. The biomimetic ion-gating properties were demonstrated by measuring the pH-tuned network "open-close" responses to charged redox probes. Such redox responses were shown to depend on the degree of protonation-deprotonation of carboxylic groups at the interparticle linkages, core sizes of the nanoparticles, and charges of the redox probes. Differences in structural networking, pH-tuning, and electrochemical gating properties were identified between the network films derived from nanoparticles of two different core sizes (2 and 5 nm). The mechanistic correlation of these structural properties was discussed. These findings have added a new pathway to the current approaches to biomimetic molecular recognition via design of core-shell nanoparticle architectures at both nanocrystal and molecular scales.

Detection of Oxidative Stress Biomarkers Using Novel Nanostructured Biosensors

“…Theoretical studies of plasmonic oscillations (Brioude et al, 2005, Draine et al, 1994, Gonzales et al, 2007, Jain et al, 2006, Kooij et al, 2006, Lee et al, 2005, 2006, Prescott et al, 2006, Ungureanu et al, 2009, Yang et al, 1995, Yin et al, 2006 and SP absorbance spectra (Alvarez et al, 1997, Etchegoin et al, 2006, Johnson et al, 1972, Kamat, 2002, Link et al, 1999a, Link et al, 1999b, Mishchenko et al, 2002, Perez-Juste et al, 2005, Ping et al, 2008 have enabled the understanding of mechanisms leading to the absorbance maximum shifts associated with the assembly processes. Extensive studies of the surface plasmon absorbance for various AuNP systems have been carried out by several groups (Alivisatos et al, 1996, Elghanian et al, 1997, Hostetler et al, 1998, Hostetler et al, 1999, Kamat, 2002, Kariuki et al, 2004, Kelly et al, 2003, Lim et al, 2009, Maye et al, 2005, Park et al, 2002, Reynolds et al, 2000, Storhoff et al, 1998, Taton et al, 2000, Taton et al, 2001, Zheng et al, 2000. In this work, the formation of networks of fluorosurfactant ZONYL-capped spherical AuNP's mediated by Hcys, and glutaraldehyde molecules have been investigated (Scheme 1).…”

Nanoparticle Assembly via Hydrogen-Bonding: IRS, TEM and AFM Characterizations

“…We have recently demonstrated [7] that hydrogen-bonding of carboxylic acid functionalized shells at gold nanocrystals of different size and shape exhibits intriguing anisotropic reactivity in terms ofcis-or trans-configuration. (Scheme 1).…”

Quantitative Detection and Fixation of Single and Multiple Gold Nanoparticles on a Microfluidic Chip by Thermal Lens Microscope

“…10 However, these methods have been used to treat many particles simultaneously, though the control of individual nanoparticles was difficult. Therefore, fixation methods that are capable of controlling the position and the number of nanoparticles are desired for fixing of individual nanoparticles.…”