The label-free optical biosensor for an automated, ultra-sensitive and highly accurate microorganisms identification

An optical biosensor for proteomic breast cancer biomarker detection in complex media is presented. Bloch Surface Waves (BSW) excited onto one dimensional photonic crystal (1DPC) were used to probe the interaction of HER2 with three antibody species and an inert protein (Bovine Serum Albumin - BSA). The optical system combines Label-Free readings to track the bioassay real-time development and Fluorescence emission quantification to evaluate the level of specific interaction between the antigen and the antibodies. The results confirm a distinguishable level of affinity between the antibodies and the analyte according to their specificity even at low antibody surface density (about 1173 pg/mm2).

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Label-free optical biosensor for real-time monitoring the cytotoxicity of xenobiotics: A proof of principle study on glyphosate

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2018.02.045 ◽

2018 ◽

Vol 351 ◽

pp. 80-89 ◽

Cited By ~ 23

Author(s):

Eniko Farkas ◽

Andras Szekacs ◽

Boglarka Kovacs ◽

Marianna Olah ◽

Robert Horvath ◽

...

Keyword(s):

Real Time ◽

Optical Biosensor ◽

Label Free ◽

Real Time Monitoring ◽

Proof Of Principle

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Aptamer Functionalized Lipid Multilayer Gratings for Label-Free Analyte Detection

Nanomaterials ◽

10.3390/nano10122433 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2433

Author(s):

Plengchart Prommapan ◽

Nermina Brljak ◽

Troy W. Lowry ◽

David Van Winkle ◽

Steven Lenhert

Keyword(s):

Lipid Composition ◽

Optical Biosensor ◽

Optical Signal ◽

Dna Aptamer ◽

Critical Parameters ◽

Label Free ◽

Scale Thickness ◽

Label Free Detection ◽

Analyte Detection ◽

Micrometer Scale

Lipid multilayer gratings are promising optical biosensor elements that are capable of transducing analyte binding events into changes in an optical signal. Unlike solid state transducers, reagents related to molecular recognition and signal amplification can be incorporated into the lipid grating ink volume prior to fabrication. Here we describe a strategy for functionalizing lipid multilayer gratings with a DNA aptamer for the protein thrombin that allows label-free analyte detection. A double cholesterol-tagged, double-stranded DNA linker was used to attach the aptamer to the lipid gratings. This approach was found to be sufficient for binding fluorescently labeled thrombin to lipid multilayers with micrometer-scale thickness. In order to achieve label-free detection with the sub-100 nm-thick lipid multilayer grating lines, the binding affinity was improved by varying the lipid composition. A colorimetric image analysis of the light diffracted from the gratings using a color camera was then used to identify the grating nanostructures that lead to an optimal signal. Lipid composition and multilayer thickness were found to be critical parameters for the signal transduction from the aptamer functionalized lipid multilayer gratings.

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Label-Free Optical Biosensing Using Low-Cost Electrospun Polymeric Nanofibers

Chemosensors ◽

10.3390/chemosensors8040119 ◽

2020 ◽

Vol 8 (4) ◽

pp. 119

Author(s):

Paula Martínez-Pérez ◽

Salvador Ponce-Alcántara ◽

Nieves Murillo ◽

Ana Pérez-Márquez ◽

Jon Maudes ◽

...

Keyword(s):

Real Time ◽

Large Scale ◽

High Surface ◽

Protein A ◽

Volume Ratio ◽

Polyamide 6 ◽

Optical Biosensor ◽

Label Free ◽

Electrospinning Technique ◽

Optical Biosensing

Polymeric nanofiber matrices are promising structures to develop biosensing devices due to their easy and affordable large-scale fabrication and their high surface-to-volume ratio. In this work, the suitability of a polyamide 6 nanofiber matrix for the development of a label-free and real-time Fabry–Pérot cavity-based optical biosensor was studied. For such aim, in-flow biofunctionalization of nanofibers with antibodies, bound through a protein A/G layer, and specific biodetection of 10 µg/mL bovine serum albumin (BSA) were carried out. Both processes were successfully monitored via reflectivity measurements in real-time without labels and their reproducibility was demonstrated when different polymeric nanofiber matrices from the same electrospinning batch were employed as transducers. These results demonstrate not only the suitability of correctly biofunctionalized polyamide 6 nanofiber matrices to be employed for real-time and label-free specific biodetection purposes, but also the potential of electrospinning technique to create affordable and easy-to-fabricate at large scale optical transducers with a reproducible performance.

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