A self-assembled fusion protein-based surface plasmon resonance biosensor for rapid diagnosis of severe acute respiratory syndrome

Abstract

A surface plasmon resonance (SPR)-based biosensor was developed for simple diagnosis of severe acute respiratory syndrome (SARS) using a protein created by genetically fusing gold binding polypeptides (GBPs) to a SARS coronaviral surface antigen (SCVme). The GBP domain of the fusion protein serves as an anchoring component onto the gold surface, exploiting the gold binding affinity of the domain, whereas the SCVme domain is a recognition element for anti-SCVme antibody, the target analyte in this study. SPR analysis indicated the fusion protein simply and strongly self-immobilized onto the gold surface, through GBP, without surface chemical modification, offering a stable and specific sensing platform for anti-SCVme detection. AFM and SPR imaging analyses demonstrated that anti-SCVme specifically bound to the fusion protein immobilized onto the gold-micropatterned chip, implying that appropriate orientation of bound fusion protein by GBP resulted in optimal exposure of the SCVme domain to the assay solution, resulting in efficient capture of anti-SCVme antibody. The best packing density of the fusion protein onto the SPR chip was achieved at the concentration of 10 microg mL(-1); this density showed the highest detection response (906RU) for anti-SCVme. The fusion protein-coated SPR chip at the best packing density had a lower limit of detection of 200 ng mL(-1) anti-SCVme within 10 min and also allowed selective detection of anti-SCVme with significantly low responses for non-specific mouse IgG at all tested concentrations. The fusion protein provides a simple and effective method for construction of SPR sensing platforms permitting sensitive and selective detection of anti-SCVme antibody.

Trends in Biosensors for HPV: Identification and Diagnosis

“…Biosensors that make use of the surface plasmonic waves of metallic substrates to detect the interaction between the target analyte and the biorecognition element are actually monitoring the change in the refractive index (RI) at the analyte-sensor interface. The RI changes produce a variation in the propagation constant of the surface plasmon wave that will produce the reading [98]. One of the signatures of SPR is its convenience as a labelfree sensing principle, avoiding the use of radioactive and fluorescence markers.…”

Highly Sensitive SPR Biosensor Based on Nanoimprinting Technology

“…As a typical example, the surface chemistry to immobilize proteins via hexahistidine tags (His-tag) has been used (Sigal et al, 1996). In recent years, mutated proteins, such as functional fusion proteins, have been used for achieving oriented immobilization of capture agents and simplification of the immobilization process (Terrettaz et al, 2002, Ha et al, 2007, Park et al, 2009, Le Brun et al, 2011. Some mutated proteins are already on the market as commercial layers (Athey et al, 2005).…”

Mixed‐monolayer of N‐hydroxysuccinimide‐terminated cross‐linker and short alkanethiol to improve the efficiency of biomolecule binding for biosensing

“…Although biological recognition elements can be immobilized on the gold surface via noncovalent or covalent interactions, covalent attachment is commonly preferred for decreasing the chance of nonspecific binding (via amine groups) in addition to generation of stable platforms . For the covalent attachment of the biological components lacking the required functional groups, linker molecules are commonly used .…”

“…Although biological recognition elements can be immobilized on the gold surface via noncovalent or covalent interactions, covalent attachment is commonly preferred for decreasing the chance of nonspecific binding (via amine groups) in addition to generation of stable platforms. [22][23][24] For the covalent attachment of the biological components lacking the required functional groups, linker molecules are commonly used. 25,26 In addition to forming an intermediate layer between the proteins/probes and the substrate, linker molecules provide stable and specific binding of the probe while orienting it towards solution, and hence increasing its chance of capturing the target molecule.…”