1,721,002 research outputs found
Determination of the minimum inhibitory concentration of Fe3+, Cu2+ and Zn2+ in Pseudomonas fluorescens
Full text linkBiomedical Applications
No full textIn recent years, 3D printing technology has become a sufficiently mature technique to allow not only the production of objects starting from a design modeling but also a possible customization through the introduction of functionality by the end user. This rapid prototyping technique represents a very promising technology for device fabrication with different application fields (e.g., biological, environmental, food, aerospace), offering advantages over traditional manufacturing methods.
Moreover, the 3D printing archetype has introduced novel opportunities for the realization of smart devices, where the added value lies in their intrinsic functionality. In fact, 3D-printed functional materials can transform their structure in response to specific stimuli (e.g., temperature, pH, light radiation, etc.), adding to the printed object interesting properties to take advantage of. Recently, this paradigm has been explored and expanded by researcher’s/engineer’s community with the aim of realizing 3D printable objects that present exploitable chemical functionalities.
In this chapter, functional 3D objects for bio-applications have been reported, combining 3D printing technology with an accurate material engineering. The result is a single step 3D-printed object with intrinsic chemical functionalities that could be exploited to produce immunoassay-based and/or enzymatically active devices for biosensing purposes and precision medicine
A new versatile method to extract features from FESEM images: a case study on rice kernels
No full textSuccinic anhydride functionalized microcantilevers for protein immobilization and quantification
No full textDetection methodologies for microRNA biomarker profiling
No full textOwing to their pivotal role as expression regulators, microRNAs (miRNAs) have different physiological roles and can be involved in the onset and progression of several diseases. For this reason, their altered presence can be predictive of a pathological state. Furthermore, the ubiquitous presence of these short RNA sequences in basically all body tissues and fluids makes them elite candidates as biomarkers. With this concept in mind, it is fundamental to have effective, sensitive, and selective techniques to perform their accurate detection and profiling. The goal of this chapter is to summarize the pros and cons of some of the available detection approaches used for miRNA profiling, starting from the most common unamplified/amplified probe-based methods to the advanced techniques based on biosensors and bioassays
Functionalized ZnO nanowires for microcantilever biosensors with enhanced binding capability
No full textAn efficient way to increase the binding capability of microcantilever biosensors is here demonstrated by growing zinc oxide nanowires (ZnO NWs) on their active surface. A comprehensive evaluation of the chemical compatibility of ZnO NWs brought to the definition of an innovative functionalization method able to guarantee the proper immobilization of biomolecules on the nanostructured surface. A noteworthy higher amount of grafted molecules was evidenced with colorimetric assays on ZnO NWs-coated devices, in comparison with functionalized and activated silicon flat samples. ZnO NWs grown on silicon microcantilever arrays and activated with the proposed immobilization strategy enhanced the sensor binding capability (and thus the dynamic range) of nearly 1 order of magnitude, with respect to the commonly employed flat functionalized silicon devices
Ag-COATED POROUS SILICON-PDMS MEMBRANES INTEGRATED IN A SERS MICROFLUIDIC DEVICE FOR LABEL FREE DETECTION OF MICRO-RNA
No full textWe report on the fabrication of an elastomeric multichamber microfluidic device hosting SERS active silvercoated
porous silicon membranes. The chip, characterized in terms of Raman efficiency (enhancements > 10 7) and
uniformity using 4-mercaptobenzoic acid (4-MBA) as non-resonant probe molecule, allows calibration of the
SERS signal intensity vs. the analyte concentration. After a suitable optimization of a functionalization protocol
the device is applied for the label free detection of microRNA tumor markers in a hybridization based biosensing
assay
Photocatalytic Disinfection of Selected Waterborne Pathogens by Visible Light-Active Nano Iron-Doped TiO2 Obtained by a Sol–Gel Method
Full text linkBacterial contamination in drinking water systems poses a serious health risk due to poor hygiene, human activities, and cross-contamination within the water supply. This study examines the potential of iron-doped titanium oxide nanometric powder (Fe-TiO2) for the photocatalytic disinfection of Gram-negative E. coli and Gram-positive S. aureus under visible light. The Fe-TiO2 photocatalyst, with an optimal nominal content of 2.5 wt % Fe, was synthesized using a surfactant-assisted sol–gel method, resulting in a mesoporous nanomaterial composed of anatase nanoparticles with a specific surface area of 123 m2/g. A sample of undoped anatase TiO2, obtained using the same sol–gel method and exhibiting a specific surface area of 116 m2/g, was utilized to confirm the role of Fe-doping in disinfection. The nanopowders were characterized using X-ray diffraction, N2 sorption at −196 °C, diffuse reflectance UV–vis spectroscopy, X-ray photoelectron spectroscopy, electrophoretic mobility measurements, high-resolution transmission electron microscopy combined with energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. Photocatalytic disinfection tests were conducted using 1 and 0.5 g/L Fe-TiO2 with varying initial bacterial concentrations, with 1 g/L yielding the most promising results under the experimental conditions employed. After 240 min of treatment with 1 g/L Fe-TiO2, a 99.9% removal of both E. coli and S. aureus was achieved starting from a bacterial concentration of 1 × 106 CFU/mL. A 99.9% removal of E. coli and a 99.8% removal of S. aureus were achieved starting from 1 × 104 CFU/mL. The Fe-TiO2 nanomaterial was effective against high concentrations of both bacteria under visible light. Reusability was studied by recovering the Fe-TiO2 nanoparticles and assessing their performance over three cycles. The photocatalytic disinfection effectiveness of Fe-TiO2 nanoparticles under visible light was validated using an actual tap water sample containing 167 CFU/mL total coliforms and 8 CFU/mL E. coli. The bacteria were photocatalytically inactivated within 30 mi
Ag DECORATED TiO2 NANOTUBE ARRAYS GROWN BY ANODIC OXIDATION AS ULTRASENSITIVE SERS SUBSTRATES FOR OPTOFLUIDIC SENSING APPLICATIONS
No full textIn this work, porous TiO2 nanostructures consisting of vertically aligned nanotube arrays were grown by anodic oxidation and decorated with silver nanoparticles employing sputtering deposition. The hybrid metal-semiconductors were used as SERS active substrates and fully integrated into microfluidic devices. Remarkable R6G limit of detection down to 10-14 M and good homogeneity of the SERS signal was found for the optimized substrates. The biosensing performance of Ag-TiO2 nanotubes based optofluidic device was tested exploiting an optimized protocol for oligonucleotides detectio
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