Application of Optical Protein-chip in Detecting Phage M13KO7

Abstract: Avidin layer was bound on the substrate surface of Silicon wafer modified with aldehyde. The interaction between avidin and biotin was adopted for the immobilization of mouse monoclonal biotin-anti-M13 (antibody GP3)-labeled biotin. The surface was incubated in a solution containing phage M13KO7, which was trapped by the antibody GP3 with the interaction between phage M13KO7 and antibody GP3, resulting in a variation of layer thickness that was detected by imaging ellipsometry. The results showed a saturated layer of antibody GP3 with a thickness about 6.9 nm on the surface of the silicon wafer. The specific interaction between phage M13KO7 and antibody GP3 resulted in a variation of layer thickness. The layer of phage M13KO7 bound with antibody GP3 was 17.5 nm in the concentration of 1.1×1010 pfu/mL. Each variation of the layer thickness corresponded to a concentration of phage M13KO7 in the range of 0.1×1010–2.5×1010 pfu/mL, with the sensitivity of 109 pfu/mL. Compared with other methods, the optical protein-chip, requiring only short measurement time, label free, is a quantitative test, and can be visualized. This study could be significant on the interactions between the antibody and the virus, showing potential in the early diagnosis of virosis.

Micro-systems for Optical Protein-Chip

Protein-Chip as micro-assays for the determination of protein interaction, the analysis, the identification and the purification of proteins has large potential applications. The Optical Protein-Chip is able to detect the multi-interaction of proteins and multi-bio-activities of molecules directly and simultaneously with no labeling. The chip is a small matrix on solid substrate containing multi-micro-area prepared by microfabrication with photolithography or soft lithography for surface patterning, and processed with surface modification which includes the physical, chemical, and bio-chemical modifications, etc. The ligand immobilization, such as protein immobilization, especially the oriented immobilization with low steric hindrance and high bio-specific binding activity between ligand and receptor is used to form a sensing surface. Each area of the pattern is corresponding to only one bioactivity. The interval between the areas is non-bioactive and optically extinctive. The affinity between proteins is used to realize non-labeling microassays for the determination of protein identification and protein interaction. The sampling of the chip is non-disturbing, performed with imaging ellipsometry and image processing on a database of proteins.

Soluble Angiopoietin Receptor Tie-2 In Patients With Acute Myocardial Infarction And Its Detection By Optical Protein-Chip

The Tie-2 receptor has been shown to play a role in angiogenesis in atherosclerosis. The conventional method assaying the level of soluble Tie-2 (sTie-2) was ELISA. However, this method has some disadvantages. The aims of this research are to establish a more simple detection method, the optical protein-chip based on imaging ellipsomtry (OPC-IE) applying to Tie-2 assay. The sTie-2 biosensor surface on silicon wafer was prepared first, and then serum levels of sTie-2 in 38 patients with AMI were measured on admission (day 1), day 2, day 3 and day 7 after onset of chest pain and 41 healthy controls by ELISA and OPC-IE in parallel. Median level of sTie-2 increased significantly in the AMI patients when compared with the controls. Statistics showed there was a significant correlation in sTie-2 results between the two methods (r=0.923, P0.01). The result of this study showed that the level of sTie-2 increased in AMI, and OPC-IE assay was a fast, reliable, and convenient technique to measure sTie-2 in serum.

Quantum dot / optical protein bio-nano hybrid system biosensing

The integration of novel nanomaterials with highly-functional biological molecules has advanced multiple fields including electronics, sensing, imaging, and energy harvesting. This work focuses on the creation of a new type of bio-nano hybrid substrate for military biosensing applications. Specifically it is shown that the nano-scale interactions of the optical protein bacteriorhodopsin and colloidal semiconductor quantum dots can be utilized as a generic sensing substrate. This work spans from the basic creation of the protein to its application in a novel biosensing system. The functionality of this sensor design originates from the unique interactions between the quantum dot and bacteriorhodopsin molecule when in nanoscale proximity. A direct energy transfer relationship has been established between coreshell quantum dots and the optical protein bacteriorhodopsin that substantially enhances the protein’s native photovoltaic capabilities. This energy transfer phenomena is largely distance dependent, in the sub-10nm realm, and is characterized experimentally at multiple separation distances. Experimental results on the energy transfer efficiency in this hybrid system correlate closely to theoretical predictions. Deposition of the hybrid system with nano-scale control has allowed for the utilization of this energy transfer phenomena as a modulation point for a functional biosensor prototype. This work reveals that quantum dots have the ability to activate the bacteriorhodopsin photocycle through both photonic and non-photonic energy transfer mechanisms. By altering the energy transferred to the bacteriorhodopsin molecule from the quantum dot, the electrical output of the protein can be modulated. A biosensing prototype was created in which the energy transfer relationship is altered upon target binding, demonstrating the applicability of a quantum dot/bacteriorhodopsin hybrid system for sensor applications. The electrical nature of this sensing substrate will allow for its efficient integration into a nanoelectronics array form, potentially leading to a small-low power sensing platform for remote toxin detection applications.

Development Of Biosensor Based On Imaging Ellipsometry

The concept of biosensor based on imaging ellipsometry was proposed ten years ago. Its principle and the methodology as well as some solutions to problems which have to be faced during the development are mentioned. Its properties of phase sensitive, high throughput and fast sampling, as well as label-free, sensitivity better than 1 ng/ml for Immunoglobulin G, and real-time analysis for protein interaction process, etc. provide a potential for applications in biomedicine field. The recent biosensing development with total internal reflection imaging ellipsometry is presented also. [GRAPHICS] An example of 48 protein arrays in matrix. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Feasibility of Protein a for the Oriented Immobilization of Immunoglobulin on Silicon Surface for a Biosensor with Imaging Ellipsometry

The feasibility of using protein A to immobilize antibody on silicon surface for a biosensor with imaging ellipsometry was presented in this study. The amount of human IgG bound with anti-IgG immobilized by the protein A on silicon surface was much more than that bound with anti-IgG immobilized by physical adsorption. The result indicated that the protein A could be used to immobilize antibody molecules in a highly oriented manner and maintain antibody molecular functional configuration on the silicon surface. High reproducibility of the amount of antibody immobilization and homogenous antibody adsorption layer on surfaces could be obtained by this immobilization method. Imaging ellipsometry has been proven to be a fast and reliable detection method and sensitive enough to detect small changes in a molecular monolayer level. The combination of imaging ellipsometry and surface modification with protein A has the potential to be further developed into an efficient immunoassay protein chip.

Protein Microarray: "Theory" to "Real Practice"

Fueled by ever-growing genomic information and rapid developments of proteomics–the large scale analysis of proteins and mapping its functional role has become one of the most important disciplines for characterizing complex cell function. For building functional linkages between the biomolecules, and for providing insight into the mechanisms of biological processes, last decade witnessed the exploration of combinatorial and chip technology for the detection of bimolecules in a high throughput and spatially addressable fashion. Among the various techniques developed, the protein chip technology has been rapid. Recently we demonstrated a new platform called “Spacially addressable protein array” (SAPA) to profile the ligand receptor interactions. To optimize the platform, the present study investigated various parameters such as the surface chemistry and role of additives for achieving high density and high-throughput detection with minimal nonspecific protein adsorption. In summary the present poster will address some of the critical challenges in protein micro array technology and the process of fine tuning to achieve the optimum system for solving real biological problems.

A Label-Free Multisensing Immunosensor Based on Imaging Ellipsometry

An immunosensor based on imaging ellipsometry and its potential applications was demonstrated in this paper. It has been proven a fast, reliable, and convenient method to quantify the thickness distribution of protein layers or detect protein concentration in solution. Combined with a protein chip, the immunosensor was able to detect multiple analytes simultaneously without any labeling. Preliminary results demonstrated how this immunosensor could be used to monitor several independent biospecific binding processes in real-time and in situ conditions.

Parabolic tapered photonic crystal cavity in silicon

We demonstrate the design, fabrication, transmission spectrum measurement, and near-field characterization of a parabolic tapered one-dimensional photonic crystal cavity in silicon. The results shows a relatively high quality factor (∼43 000), together with a small modal volume of ∼ 1. 1 (λ/n) 3. Moreover, the design allows repeatable device fabrication, as evident by the similar characteristics obtained for several tens of devices that were fabricated and tested. These demonstrated 1D PhC cavities may be used as a building block in integrated photonic circuits for optical on-chip interconnects and sensing applications. © 2012 American Institute of Physics.

Functionalized Ag nanoparticles with tunable optical properties for selective protein analysis

We present a preparation procedure for small sized biocompatibly coated Ag nanoparticles with tunable surface plasmon resonances. The conditions were optimised with respect to the resonance Raman signal enhancement of heme proteins and to the preservation of the native protein structure....

Future switching technology: bacterial protein-based programmable all-optical switch for integrated optics applications?

We report on the bacterial protein-based all-optical switches which operate at low laser power, high speed and fulfil most of the requirements to be an ideal all-optical switch without any moving parts involved. This consists of conventional optical waveguides coated with bacteriorhodopsin films at switching locations. The principle of operation of the switch is based on the light-induced refractive index change of bacteriorhodopsin. This approach opens the possibility of realizing proteinbased all-optical switches for communication network, integrated optics and optical computers.

Sensitive detection of C-reactive protein using optical fiber Bragg gratings

An accurate and highly sensitive sensor platform has been demonstrated for the detection of C-reactive protein (CRP) using optical fiber Bragg gratings (FBGs). The CRP detection has been carried out by monitoring the shift in Bragg wavelength (Delta lambda(B)) of an etched FBG (eFBG) coated with an anti-CRP antibody (aCRP)-graphene oxide (GO) complex. The complex is characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. A limit of detection of 0.01 mg/L has been achieved with a linear range of detection from 0.01 mg/L to 100 mg/L which includes clinical range of CRP. The eFBG sensor coated with only aCRP (without GO) show much less sensitivity than that of aCRP-GO complex coated eFBG. The eFBG sensors show high specificity to CRP even in the presence of other interfering factors such as urea, creatinine and glucose. The affinity constant of similar to 1.1 x 10(10) M-1 has been extracted from the data of normalized shift (Delta lambda(B)/lambda(B)) as a function of CRP concentration. (C) 2014 Elsevier B.V. All rights reserved.