Characterization of Recombinant His-Tag Protein Immobilized onto Functionalized Gold Nanoparticles

Abstract

The recombinant polyhistidine-tagged hemoglobin I ((His)6-rHbI) from the bivalve Lucina pectinata is an ideal biocomponent for a hydrogen sulfide (H2S) biosensor due to its high affinity for H2S. In this work, we immobilized (His)6-rHbI over a surface modified with gold nanoparticles functionalized with 3-mercaptopropionic acid complexed with nickel ion. The attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) analysis of the modified-gold electrode displays amide I and amide II bands characteristic of a primarily α-helix structure verifying the presence of (His)6-rHbI on the electrode surface. Also, X-ray photoelectron spectroscopy (XPS) results show a new peak after protein interaction corresponding to nitrogen and a calculated overlayer thickness of 5.3 nm. The functionality of the immobilized hemoprotein was established by direct current potential amperometry, using H2S as the analyte, validating its activity after immobilization. The current response to H2S concentrations was monitored over time giving a linear relationship from 30 to 700 nM with a corresponding sensitivity of 3.22 × 10−3 nA/nM. These results confirm that the analyzed gold nanostructured platform provides an efficient and strong link for polyhistidine-tag protein immobilization over gold and glassy carbon surfaces for a future biosensors development.

Biogenic Ag Nanoparticles from Neem Extract: Their Structural Evaluation and Antimicrobial Effects against Pseudomonas nitroreducens and Aspergillus unguis (NII 08123)

“…33 The deconvoluted N 1s spectrum (Figure 5f) shows two nitrogen species at binding energies 399.1 and 400.8 eV corresponding to C−NH 2 34 and H−N−CO of amide-N, aromatic-N, and amine-N of proteins. 35 The functional groups present on EENL-AgNPs confirm the biomass capping.…”

“…The deconvoluted O 1s spectrum (Figure e) shows three oxygen species at binding energies 532.7, 533.5, and 531.3 eV corresponding to the O–CO oxygen double bond in carboxylic acid, C–O and −CO of the biomass molecules present on the surface of the AgNPs meant to stabilize them, and O due to AgO . The deconvoluted N 1s spectrum (Figure f) shows two nitrogen species at binding energies 399.1 and 400.8 eV corresponding to C–NH 2 and H–N–CO of amide-N, aromatic-N, and amine-N of proteins . The functional groups present on EENL-AgNPs confirm the biomass capping.…”

In vivo oral insulin delivery via covalent organic frameworks

“…S25c † shows the O 1s XPS survey spectrum in insulin, where the peak is composed of three components centered at 531.4, 532.3 and 533.5 eV attributed to oxygen in carboxylate, amide and alcohol groups respectively. 67 After loading the TTA-DFP-nCOF with insulin, an important decrease ( ca. 12%) in the percentage of oxygen assigned to carboxylate was observed (Fig.…”

Development of nanometer-thick graphite film extreme ultraviolet pellicle with hydrogen-resistant TiN capping layer

“…Overall, the high-energy region is broadened; hence, there are other bonds besides the O-N bonds. The C 1s peak was decomposed into five peaks corresponding to sp2 bonds (284.6 eV), sp3 bonds (285.4 eV), C-NH bonds (286.1 eV), C=O (287 eV), and O=C-N (288.7 eV) [38]. Cruz-Silva has provided some evidence of the existence of sp3 bonding between defective graphene layers through simulations [39].…”