Arginine‐glycine‐aspartate ( RGD ) peptide‐modified graphene as efficient support material for Pt electrocatalyst in proton exchange membrane fuel cells

Abstract

Graphene with its two-dimensional structure and unique properties has immense potential in energy-related applications such as proton exchange membrane (PEM) fuel cells. Herein, we employ a well-known biomolecule arginine-glycine-aspartate (RGD) peptide-functionalized graphene-supported Pt nanoparticles as an electrocatalyst for PEM fuel cells for the first time. First, chemically reactive graphene oxide (GO) is used as a precursor to covalently functionalize it with RGD peptide through amide bond formation. The amino moieties of RGD peptide on graphene surface serve as ligands and active sites for the nucleation and controlled growth of Pt nanoparticles through polyol reduction method. The homogeneous distribution of ultra-small (about 3 nm) Pt nanoparticles supported on RGD functionalized graphene boosted the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) electrocatalytic activities by 52% in electrochemical active surface area (ECSA), 112% in mass activity, and 39% in specific activity as compared to unmodified graphene surface. The strong interaction between the metal and the modified support's surface, assisted in evading serious agglomeration and dissolution during 1000 cycles of accelerated degradation tests (ADT), improving the longterm durability of the Pt electrocatalyst by showing about 21% higher ECSA retention than the unmodified support. Fuel cell performance of RGD functionalized graphene-supported Pt nanoparticles also depicted improved power output due to its better Pt utilization and electrocatalytic activity.

An Fe-organic framework/arginine–glycine–aspartate peptide-modified sensor for electrochemically detecting nitric oxide released from living cells

“…The bands at 2958 and 1200 cm −1 correspond to the stretching vibrations of alkane ( ν CH) and aliphatic amine ( ν C–N), respectively, in the backbone of the RGD peptide, whereas the band at 1133 cm −1 corresponds to the stretching vibrations of the epoxy group ( ν C–O). 27 Furthermore, the broad band near 3423 cm −1 and the weak band around 3219 cm −1 originate from ν OH and ν NH, respectively. The bands at 1427 and 1370 cm −1 are primarily due to δ CH, whereas the bands at 840, 800, and 723 cm −1 correspond to γCH.…”

“…25 A short arginine–glycine–aspartic (RGD) amino acid sequence tripeptide, present in several extracellular matrix (ECM) proteins, serves as a primary recognition site for cell-membrane integrin receptors that mediate cell adhesion to the ECM, 26 which are used to stimulate cell adhesion and growth. 27 Experiments on HUVEC attachment in vitro demonstrated that RGD-grafted substrates significantly enhanced cell attachment. 28 Therefore, Fe–BTC/RGD/SPE was prepared via a combination of Fe–BTC having electrocatalytic performance toward NO with RGD promoting cell adhesion and growth and it was utilized for the rapid and sensitive detection of NO released from HUVECs.…”