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1.
Sensors (Basel) ; 21(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806753

RESUMO

In this paper, we present the development of a photonic biosensor device for cancer treatment monitoring as a complementary diagnostics tool. The proposed device combines multidisciplinary concepts from the photonic, nano-biochemical, micro-fluidic and reader/packaging platforms aiming to overcome limitations related to detection reliability, sensitivity, specificity, compactness and cost issues. The photonic sensor is based on an array of six asymmetric Mach Zender Interferometer (aMZI) waveguides on silicon nitride substrates and the sensing is performed by measuring the phase shift of the output signal, caused by the binding of the analyte on the functionalized aMZI surface. According to the morphological design of the waveguides, an improved sensitivity is achieved in comparison to the current technologies (<5000 nm/RIU). This platform is combined with a novel biofunctionalization methodology that involves material-selective surface chemistries and the high-resolution laser printing of biomaterials resulting in the development of an integrated photonics biosensor device that employs disposable microfluidics cartridges. The device is tested with cancer patient blood serum samples. The detection of periostin (POSTN) and transforming growth factor beta-induced protein (TGFBI), two circulating biomarkers overexpressed by cancer stem cells, is achieved in cancer patient serum with the use of the device.


Assuntos
Técnicas Biossensoriais , Neoplasias , Humanos , Interferometria , Neoplasias/diagnóstico , Neoplasias/terapia , Óptica e Fotônica , Fótons , Reprodutibilidade dos Testes
2.
Langmuir ; 33(4): 848-853, 2017 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-28040898

RESUMO

In this paper, we present the immobilization of thiol-modified aptamers on alkyne- or alkene-terminated silicon nitride surfaces by laser-induced click chemistry reactions. The aptamers are printed onto the surface by laser-induced forward transfer (LIFT), which also induces the covalent bonding of the aptamers by thiol-ene or thiol-yne reactions that occur upon UV irradiation of the thiol-modified aptamers with ns laser pulses. This combination of LIFT and laser-induced click chemistry allows the creation of high-resolution patterns without the need for masks. Whereas the click chemistry already takes place during the printing process (single-step process) by the laser pulse used for the printing process, further irradiation of the LIFT-printed aptamers by laser pulses (two-step process) leads to a further increase in the immobilization efficiency.

3.
Bioengineering (Basel) ; 6(4)2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658719

RESUMO

Bioprinting techniques can be used for the in vitro fabrication of functional complex bio-structures. Thus, extensive research is being carried on the use of various techniques for the development of 3D cellular structures. This article focuses on direct writing techniques commonly used for the fabrication of cell structures. Three different types of bioprinting techniques are depicted: Laser-based bioprinting, ink-jet bioprinting and extrusion bioprinting. Further on, a special reference is made to the use of the bioprinting techniques for the fabrication of 2D and 3D liver model structures and liver on chip platforms. The field of liver tissue engineering has been rapidly developed, and a wide range of materials can be used for building novel functional liver structures. The focus on liver is due to its importance as one of the most critical organs on which to test new pharmaceuticals, as it is involved in many metabolic and detoxification processes, and the toxicity of the liver is often the cause of drug rejection.

4.
Biosens Bioelectron ; 81: 388-394, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26995284

RESUMO

A novel nanoparticle based biosensor for the fast and simple detection of DNA hybridization events is presented. The sensor utilizes hybridized DNA's charge transport properties, combining them with metallic nanoparticle networks that act as nano-gapped electrodes. The DNA hybridization events can be detected by a significant reduction in the sensor's resistance due to the conductive bridging offered by hybridized DNA. By modifying the nanoparticle surface coverage, which can be controlled experimentally being a function of deposition time, and the structural properties of the electrodes, an optimized biosensor for the in situ detection of DNA hybridization events is ultimately fabricated. The fabricated biosensor exhibits a wide response range, covering four orders of magnitude, a limit of detection of 1nM and can detect a single base pair mismatch between probe and complementary DNA.


Assuntos
Técnicas Biossensoriais/instrumentação , DNA/análise , Nanopartículas Metálicas/química , Hibridização de Ácido Nucleico , Platina/química , Pareamento Incorreto de Bases , Técnicas Biossensoriais/economia , DNA/genética , Condutividade Elétrica , Técnicas Eletroquímicas/economia , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento
5.
Adv Mater ; 27(13): 2231-5, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25708570

RESUMO

Superamphiphobic, (quasi-)ordered plasma-textured surfaces, coated with a perfluorinated monolayer, exhibit extreme resistance against drop-pinning for both water-like and low-surface-tension mixtures (36 mN m(-1)). The highest values reported here are 36 atm for a water-like mixture, 5 times higher than previously reported in the literature, and 7 atm for a low-surface-tension mixture, the highest ever reported value for lotus-leaf-inspired surfaces.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Lasers , Microtecnologia/métodos , Nanotecnologia/métodos , Polímeros/química , Água/química , Gases em Plasma/química , Tensão Superficial
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