Permselectivity and Dopamine Detection with Pt Electrodes Covered with PAA-Modified Porous Silicate Film

Abstract

A novel carboxyl-group functionalized silicate nanopore films (SNFs) was successfully fabricated on Pt electrode by immobilization of the composite material containing polyacrylic acid (PAA) and tetraethyl orthosilicate (TEOS). The composite films have relatively uniform pores with an average of 20 nm in diameter and are endowed with a great amount of carboxyl groups, which provided large amount of negative charge on film surface. Scanning electron microscope (SEM), Transmission electron microscope (TEM) images, EDS spectrum and FTIR spectrum have been used to characterize the prepared SNFs. Three redox species with different charge, including hexacyanoferrate (Fe(CN)63−), hexaamino-ruthenium (Ru(NH3)63+) and ferrocene methanol (FcMeOH) in different pH, were employed to investigate the permselectivity of the SNFs modified electrode. The results showed that the SNFs modified electrode favored the mass transport of oppositely charged species (Ru(NH3)63+), repelled similarly charged species (Fe(CN)63−), and had little effect on the transport of neutral species (FcMeOH). Based on this good permselective property, the prepared SNFs modified electrode was employed to detect dopamine (DA) in the presence of ascorbic acid (AA) at pH 7.6. The prepared SNFs electrode exhibited a good sensing performance for detection of DA with the linear range of 10–1900 μM and the detection limit of 1.7 μM (S/N = 3).

Dopamine-Sensing Characteristics and Mechanism by Using N2/O2 Annealing in Pt/Ti/n-Si Structure

“…However, the sensing mechanism is important, which is explained below. [8,10,11,20,21]. (The short forms are defined here, PAA-SNFs/Pt: polyacrylic acid silicate nanopore films on Pt, GPtNPs-GCE: platinum nanoparticles-decorated graphene-modified glassy carbon electrode, Pt@NP-AuSn/Ni/CFP: Pt nanoparticle-modified nanoporous AuSn(Pt@NP-AuSn) alloy on Ni-buffered flexible carbon fiber paper (CFP), Au@Pt/GO/GCE: Au@Pt nanoflowers supported on graphene oxide, PtNi@MoS 2 : PtNi bimetallic nanoparticles loaded MoS 2 nanosheets).…”

pH-Responsive Ultrathin Nanoporous SiO2 Films for Selective Ion Permeation

“…In the recent decades, external stimulus-responsive NP SiO 2 thin films have been reported as an emerging field for many applications using their selective ion/molecular transportation abilities. , Functionalization of nanopores using stimulus-responsive molecules that react to external perturbation such as temperature, , pH, − light, , and ionic strength , affords further control of nanopore accessibility, transportation, and release properties. Especially, responsive polymer functionalization using surface-initiated polymerization such as atom transfer radical polymerization (ATRP), , reversible addition–fragmentation chain transfer (RAFT) polymerization, , nitroxide-mediated radical polymerization (NMP), and photoinitiator-mediated polymerization (PIMP) , has been adopted widely for nanopore modification.…”

Fabrication, Characterization, and Analytical Application of Silica Nanopore Array-Modified Platinum Electrode

“…And the solution pH can modulate the flux of charged probes through nanopores. More recently, Li et al have fabricated a carboxyl-functionalized silicate nanopore films on the surface of Pt electrode . In addition to studying permselectivity, the prepared electrode was employed to detect dopamine in the presence of ascorbic acid, which exhibited a good sensing performance.…”