0000000000773008
AUTHOR
F. Cavaleri
Human Topoisomerase I interaction with DNA on flexible nylon substrate for malaria diagnosis
The study of interaction between human Topoisomerase I (hTopo I) and the appropriate sequences of DNA is shown, with the aim to realize a biosensor for malaria diagnosis. Topoisomerases alter the topological state of DNA by catalysing the breaking and rejoining of DNA strands1. The ligase activity is fundamental for our biosensing strategy, revealing the pathology. hTopo I was chosen as a model system for the Plasmodium analogous. The biosensor is a new flexible and easy to degrade biochip printed on nylon by dip-pen lithography (DPL). It is realized exploiting the high specificity of complementary ssDNA2 and hTopo I ligase activity. DPL operation needs ultra-low amounts of DNA (0.5 µL) to …
Self-cleaning materials active in the visible range based on porphyrin-sensitised titanium dioxide
In the last decades, nanostructured semiconductors played a central role in the material science scene because of their numerous applications spanning from renewable energy to organic/hybrid electronics up to photocatalysis. Titanium dioxide is one of the most used semiconductors because of its low cost, chemical stability, sustainability and versatility. Indeed, it is widely employed as photo-active or charge- transporting material in electronic devices, as photocatalyst in water de-pollution treatments etc.. Remarkably, one of the most interesting application of titanium dioxide consists of the protection and conservation of cultural heritages. Actually, TiO2 photocatalytic properties are…
Spontaneous Interfacial Fragmentation of Inkjet Printed Oil Droplets and Their electrical characterization
This work presents the fabrication of femtoliter-scale oil droplets by inkjet printing based on a novel mechanism for the spontaneous fragmentation at the interface with an immiscible water phase and the electrical characterization of the resulting immersed “daughter” droplets. [1] In particular, picoliter-scale fluorinated oil droplets impact on surfactant laden water phase at moderately high Weber number (101), and are subjected to spreading and capillary instabilities at the water/air interface which ultimately lead to rupture in smaller sized droplets, according to reported models for macroscale droplets systems - [2] the emerging fragmentation results in “daughter” droplets having volu…
On the Effect of Downscaling in Inkjet Printed Life-Inspired Compartments
The fabrication of size-scalable liquid compartments is a topic of fundamental importance in synthetic biology, aiming to mimic the structures and the functions of cellular compartments. Here, inkjet printing is demonstrated as a customizable approach to fabricate aqueous compartments at different size regimes (from nanoliter to femtoliter scale) revealing the crucial role of size in governing the emerging of new properties. At first, inkjet printing is shown to produce homogenous aqueous compartments stabilized by oil-confinement with mild surfactants down to the hundreds of picoliter scale [1]. Raster Image Correlation Spectroscopy allows to monitor few intermolecular events by the involv…
Molecular Confinement in Femtoliter scale aqueous Compartments
Molecular confinement is known to lead to acceleration of molecular dynamics along with surface interaction. Nature employs confinement in molecularly crowded, heterogeneous and, specialized femtoliter (fL) compartments inside living cells for spontaneously achieving higher reaction efficiency and spatial-programming of composite, multi-step biochemical processes. We here show the facile production of aqueous fL droplets for studying molecular confinement on a biochip. We prepare fL aqueous droplets in oil drops on solid substrates by a “field-free”- no external electric fields and electrolytes - piezoelectric inkjet printing in which a novel actuating waveform is employed by picoliter size…
Interfacial fragmentation and electrical characterization of inkjet printed dil droplets
This work presents a novel mechanism for the spontaneous fragmentation of picoliter-scale oil droplets at the interface with an immiscible water phase, and the electrical characterization of the resulting immersed “daughter” droplets by an electrical impedance chip (see Figure). [1] In particular, picoliter-scale fluorinated oil droplets are produced by inkjet printing at velocity higher than 5 m/s. Upon impact on the surfactant laden water phase at moderately high Weber number , i.e. around 10, the oil droplet is subjected to spreading and capillary instabilities at the water/air interface. These ultimately lead to its rupture in smaller sized droplets, according to the reported models for…