Search results for " BIOSENSORS."
showing 10 items of 23 documents
Affinity Sensors for the Diagnosis of COVID-19
2021
The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxyge…
Hybrid, multiplexed, functional DNA nanotechnology for bioanalysis
2015
We herein aim to report on the fabrication of DNA nano-heterostructures usable as a robust multi-functional analytical system to obtain multiple and complex data in parallel format from a single sample with unprecedented analytical performances. The ability of chemical information contained in the sequences of programmed DNA structures to organize matter made DNA become a unique material in “the nanoworld”. Such carefully designed DNA nanostructures can then be functionalized/templated with different biomolecules/nanomaterials as different as nanoparticles, nanowires, organic molecules, peptides, and proteins with controlled spacing on the nanometer scale (<10 nm). In this way, it is possib…
Label-free wavelength and phase detection based SMS fiber immunosensors optimized with cladding etching
2018
The performance of E-SMS (Etched Singlemode-Multimode-Singlemode) optical fiber structures as immunosensors has been assessed by the implementation of antibody/antigen immunoassays. Through this procedure it has been proven that E-SMS structures are effective and suitable optical platforms for label-free biosensing. Using the phase shift and tracking the wavelength response it was found that the fabricated E-SMS devices exhibited limits of detection (LOD) down up to concentrations of 0.2mg/L of antigens in solution. This was achieved by coating the E-SMS with an antibody-based biolayer (goat IgG) that is able to determine the presence of anti-goat IgG antigen. Both a wavelength detection an…
Ink-Jet Printing for drug srreening on microarrays: from covalent approaches to in-liquid-droplets assays
2012
Drug screening is the complex process of retrieving chemical compounds able to modulate the activity of biological targets which are of interest for certain diseases. Conventional miniaturized drug screening technologies are based on robotic dispensers coupled with microwell arrays. However these devices require time and reagent consuming (micro-, nanoliter scale) instrumental tools, liquid handling robotics and complex detectors. Here we show a low-cost and efficient drug screening methodology based on inkjet printing for delivering molecular systems in picoliter volumes coupled with easily-implemented detection tools for probing target-drug interaction. We firstly show up a screening plat…
Luminometric Sub-nanoliter Droplet-to-droplet Arrays (LUMDA-chip) for Drug Screening on Phase I Metabolism Enzymes
2013
Here we show the fabrication of the Luminometric Sub-nanoliter Droplet-to-droplet Array (LUMDA chip) by inkjet printing. The chip is easy to be implemented and allows for amultiplexed multi-step biochemical assay in sub-nanoliter liquid spots. This concept is here applied to the integral membrane enzyme CYP3A4, i.e. themost relevant enzymatic target for phase I drug metabolism, and to some structurally-related inhibitors.
Micro and Nano patterns for Biosensing: from enzymatic assays to single cells interaction arrays
2012
In this thesis work, solution dispensing techniques have been employed for the realization of complex biological arrays. Inkjet printing techniques were employed for the generation of drug screening platforms. This approach was initially proved with a model enzyme system like Glucose Oxidase substrate covalently linked to a functionalized silicon oxide support. On this support an enzymatic substrate (D-glucose)/inhibitor (D-glucal) couple was accurately dispensed. A simple optical detection method was used to prove the screening capability of the microarray with the possibility to assay with high reproducibility at the single spot level. Afterwards, this methodology has been extended to CYP…
Imbibition of Femtoliter-Scale DNA-Rich Aqueous Droplets into Porous Nylon Substrates by Molecular Printing
2019
This work presents the first reported imbibition mechanism of femtoliter (fL)-scale droplets produced by microchannel cantilever spotting (μCS) of DNA molecular inks into porous substrates (hydrophilic nylon). Differently from macroscopic or picoliter droplets, the downscaling to the fL-size leads to an imbibition process controlled by the subtle interplay of evaporation, spreading, viscosity, and capillarity, with gravitational forces being quasi-negligible. In particular, the minimization of droplet evaporation, surface tension, and viscosity allows for a reproducible droplet imbibition process. The dwell time on the nylon surface permits further tuning of the droplet lateral size, in acc…
Layered Double Hydroxides in Bioinspired Nanotechnology
2020
Layered Double Hydroxides (LDHs) are a relevant class of inorganic lamellar nanomaterials that have attracted significant interest in life science-related applications, due to their highly controllable synthesis and high biocompatibility. Under a general point of view, this class of materials might have played an important role for the origin of life on planet Earth, given their ability to adsorb and concentrate life-relevant molecules in sea environments. It has been speculated that the organic–mineral interactions could have permitted to organize the adsorbed molecules, leading to an increase in their local concentration and finally to the emergence of life. Inspired by nature, material s…
Plasmonic Biosensors for the Detection of Lung Cancer Biomarkers: A Review
2021
Lung cancer is the most common and deadliest cancer type globally. Its early diagnosis can guarantee a five-year survival rate. Unfortunately, application of the available diagnosis methods such as computed tomography, chest radiograph, magnetic resonance imaging (MRI), ultrasound, low-dose CT scan, bone scans, positron emission tomography (PET), and biopsy is hindered due to one or more problems, such as phenotypic properties of tumours that prevent early detection, invasiveness, expensiveness, and time consumption. Detection of lung cancer biomarkers using a biosensor is reported to solve the problems. Among biosensors, optical biosensors attract greater attention due to being ultra-sensi…
Porous Aluminium Oxide Coating for the Development of Spectroscopic Ellipsometry Based Biosensor: Evaluation of Human Serum Albumin Adsorption
2020
An electrochemically synthesised porous anodic aluminium oxide (pAAO) layer has been analysed by means of spectroscopic ellipsometry. The determined thickness of the formed pAAO layer obtained from spectroscopic ellipsometry measurements and modelling was 322.75 ±