Real-Time Binding Monitoring between Human Blood Proteins and Heavy Metal Ions in Nanoporous Anodic Alumina Photonic Crystals

Abstract

This study reports on the real-time binding assessment between heavy metal ions and blood proteins immobilized onto nanoporous anodic alumina photonic crystals (NAA-PCs) by reflectometric interference spectroscopy (RIfS). The surface of NAA-PCs is chemically functionalized with γ-globulin (GG), transferrin (TFN), and serum albumin (HSA), the major proteins present in human blood plasma. Protein-modified NAA-PC platforms are exposed to analytical solutions of mercury ions of different concentrations. Dynamic changes in the effective optical thickness of protein-modified NAA-PCs in response to heavy metal ions are assessed in real time to evaluate the binding kinetics, affinity, and mechanism. Protein molecules undergo conformational changes upon exposure to mercury ions, with HSA exhibiting the strongest affinity. The combination of protein-modified NAA-PCs with RIfS allows real-time monitoring of protein-heavy metal ions interactions under dynamic flow conditions. This system is capable of detecting dynamic conformational changes in these proteins upon exposure to heavy metal ions. Our results provide new insights into these binding events, which could enable new methodologies to study the toxicity of heavy metal ions and other biomolecular interactions.

Environmental Copper Sensor Based on Polyethylenimine-Functionalized Nanoporous Anodic Alumina Interferometers

“…However, for [Cu 2+ ] ≥ 50 ppm, the reaction rate becomes almost constant and practically independent of [Cu 2+ ], indicating that the reaction is rate-limited by the binding affinity between PEI-GA-PEI and Cu 2+ ions and the conformational changes of PEI molecules upon initial exposure to Cu 2+ ions. 52 Note that control experiments with NAA interferometers without PEI-GA-PEI functional layers were performed to verify that red-shifts in the ΔOT eff of PEI-GA-PEI-functionalized NAA interferometers upon exposure to copper ions are exclusively due to selective surface chemistry interactions. Bare NAA interferometers were exposed to 10 and 100 mg L –1 analytical solutions of Cu 2+ ions at pH 5.…”

Recent Advances in Nanoporous Anodic Alumina: Principles, Engineering, and Applications

“…To provide overview of many functionalities discussed in Sections 4.1-4.7, they are gathered in the Table 2. [190] Gradient-index filters [191] Distributed Bragg reflectors [192] Optical bandpass filters [193] Human protein heavy ions real-time interaction monitoring [194] Tailoring of optical properties with pulse anodization [149] Design of phase shift defect in effective refractive index [195] Hybrid distributed DBRs and apodized GIF photonic structure [196] Characterization of thermotropic ferroelectric liquid crystals confined in the NAA [197][198][199] Glass transition of discotic liquid crystals in one-dimensional fluid [200] Adjustable optical anisotropy by self-assembly of liquid crystals confined in porous structure [201] Sensors NAA template-assisted fabrication of chromium substrate for SERS detection of heavy ions in aqueous solutions [202] Au NPs array on NAA for SERS detection of hemoglobin [203] Controlled fabrication of periodic plasmonic dimer arrays for SERS [204] Graphene-NAA composite for SERS sensing [205] Label-free optical sensor based on interferometric reflectance spectroscopy for TNF-α detection [206] NAA-based interferometer for copper sensing [207] In vivo nanotubes nanotoxicity study on murine model […”

Advances in Optical Biosensors and Sensors Using Nanoporous Anodic Alumina

“…The low detection limit was calculated at 12 nM. The sensitivity of the proposed IRS-based sensor was higher than previous IRS-based sensors that have been used for heavy metal sensing [ 136 , 137 , 138 , 139 , 140 , 141 ]. It was also investigated the selectivity of the Pb 2+ ion sensor towards interfering ions, such as Zn 2+ , Cu 2+ , Ni 2+ , Bi 3+ , Sn 2+ , Co 2+ , and Hg 2+ , in the presence of SCN − ions as a masking agent and also as a biosensor for the determination of Pb 2+ ions in seawater.…”