Silk fibroin-antigenic peptides-YVO 4 :Eu 3+ nanostructured thin films as sensors for hepatitis C

Abstract

a b s t r a c tNanostructured films prepared by Layer-by-Layer technique and containing silk fibroin, antigenic peptide NS5A-1 derived from hepatitis C virus (HCV) NS5A protein and YVO 4 :Eu 3 þ luminescent nanoparticles, were utilized in sensing of hepatitis C. Detection system exploits the biorecognition between the antibody anti-HCV and the antigenic peptide NS5A-1 through changes in luminescence properties. Films deposition was monitored by UV-vis Absorption and Fluorescence Spectroscopy measurements at each bilayer deposited. The Eu 3 þ luminescence properties were evaluated in the presence of anti-HCV for optical detection of specific antibody and anti-HIV used as negative control. Significant changes in luminescence were observed in the presence of anti-HCV concentrations. A new immunosensor platform is proposed for optical detection of hepatitis C.& 2015 Elsevier B.V. All rights reserved. Recently, our group reported an electrochemical immunosensor for HCV that explores biorecognition between an antigenic peptide (PPLLESWKDPDYVPPWHG) derived from the HCV NS5A-1 protein and anti-HCV [19], where the peptide was immobilized into Layerby-Layer (LbL) films, alternated with silk fibroin (SF). Using cyclic voltammetry, it was possible to detect the anti-HCV antibody for concentrations between 0.01 and 0.2 μg mL À 1 .

Construction and Potential Applications of Biosensors for Proteins in Clinical Laboratory Diagnosis

“…In order to develop a highly sensitive and specific immunosensor, a molecular recognition element (MRE) with a high affinity must firstly be immobilized onto the sensing interface. Specific antibodies/antigens [ 33 , 35 ] and aptamers [ 36 ] are two kinds of well-established MREs ( Figure 1 ). The antigen–antibody reaction is the basis of immunoanalysis in clinical laboratories, and modern immuno-labeling techniques using highly sensitive substances as labels have further broadened the scope of immunological techniques.…”

“…To enhance detection sensitivity, various signal amplification strategies have been combined with biosensing platforms [ 2 , 21 , 32 , 33 , 43 , 44 ]. For example, a dual signal amplification strategy was employed in fabricating ultrasensitive EC immunosensor for alpha fetoprotein (AFP) detection [ 32 ].…”

“…The analytical performance of PL immunosensors, similar to that of EC biosensing, has been largely improved by a combination of nano-techniques [ 33 , 35 , 49 , 50 ]. Lima et al [ 33 ] reported a sensing platform for an anti-hepatitis C virus (HCV) antibody using YVO 4 :Eu 3+ luminescent NPs as a PL probe ( Figure 5 ). The peptide NS5A-1 derived from HCV NS5A protein together with the NPs was immobilized layer by layer (LbL) onto silk fibroin, by which the anti-HCV antibody was detected in the range of 0~0.01 μg mL −1 .…”

“…With plenty of advantages, such as strong specificity to targets, rapid analysis, high accuracy, easy operation, and low cost, biosensors have expansive applications for diverse targets, including cyclic drugs [ 20 ], proteins [ 21 , 22 , 23 ], nucleic acids [ 24 , 25 , 26 , 27 ], and cyclic tumor cells [ 28 , 29 , 30 ]. Immunosensors have played a crucial role in the determination of tumor markers [ 31 , 32 , 33 ], significantly improving early diagnosis and prognosis of various cancers. Molecular identification unit is the basis of specific determination, which specifically recognizes and captures the target, and then induces a series of physical or chemical changes.…”

Eco-friendly polydimethylsiloxane-based self-supporting film containing europium-polyoxometalate: A flexible luminescent material for white light generation

“…Generally, a suitable host material is one which has high transparency in the wavelength range of interest, has low phonon energy and good photostability. The most common matrices for Ln 3+ ions include inorganic oxides (Y 2 O 3 , Gd 2 O 3 ) [19][20][21], halides (NaYF 4 , LiYF 4 ) [22], vanadate (YVO 4 , GdVO 4 ) [23][24][25], sulfate (NaGd(SO 4 ) 2 ) [26] and polyoxometalates (POMs) and their derivatives [27]. The halides-based materials possess low phonon energies (< 350 cm −1 ) but they are hygroscopic in nature.…”