INESC MN Microsystems and Nanotechnologies

Lisbon, Portugal

INESC MN Microsystems and Nanotechnologies

Lisbon, Portugal
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Cardoso R.,University of Lisbon | Sarapajevaite G.,INESC MN Microsystems and Nanotechnologies | Korsun O.,INESC MN Microsystems and Nanotechnologies | Cardoso S.,University of Lisbon | Ilharco L.,University of Lisbon
Canadian Geotechnical Journal | Year: 2017

Currently there are no small sensors that can be incorporated inside soil samples for laboratory testing, to monitor water transport during loading. This is an important limitation to a better understanding of the hydromechanical coupled behaviour of soils. A sol-gel relative humidity sensor (11 mm × 11 mm), microfabricated in a clean room environment, was conceived to be incorporated in soil specimens during standard laboratory tests. The sensor operates based on changes in electrical resistivity detected by a cerium-doped silica-titania film deposited using a sol-gel technique over interdigitated aluminium electrodes spaced at 300 μm. To the best of the authors’ knowledge, sol-gel sensors for relative humidity measurement have never been used in soils; therefore, this is a novel application. The water retention curve of compacted kaolin was measured with the sensors and compared with the curve found using water dewpoint potentiometer WP4-C. The sensors were also tested incorporated in an oedometer cell, in which load was applied under vapour equilibrium. It was possible to detect the increment of the degree of saturation during compression. The use of the developed sensors incorporated in soils is considered acceptable for suction ranges between 1 and 10 MPa, which extends the suction interval covered by tensiometers, normally operating up to 2 MPa. Although the sensors require improvements in terms of sol-gel deposition and calibration protocol, the results confirm their scientific potential for being used in testing and characterization of unsaturated soils. © 2017, Canadian Science Publishing. All rights reserved.


Dias T.M.,INESC MN Microsystems and Nanotechnologies | Dias T.M.,IBB Institute for Biotechnology And Bioengineering | Cardoso F.A.,INESC MN Microsystems and Nanotechnologies | Martins S.A.M.,INESC MN Microsystems and Nanotechnologies | And 5 more authors.
Analytical Methods | Year: 2016

Cell-free DNA (cfDNA) is foreseen as a promising source for liquid biopsies in cancer diagnostics. Despite its promise, methods available for its evaluation lack in robustness or, in the case of next-generation sequencing (NGS), are extremely sensitive but overly complex for routine operation. In contrast to NGS, integrated lab-on-chip devices offer advantages particularly in terms of automation, cost and speed. These devices, however, have rarely demonstrated the detection of biologically relevant DNA fragments originating from blood. To this end, we present a strategy for the magnetic labeling and detection of cfDNA fragments, using an array of 30 magnetoresistive (MR) sensors integrated in a portable biochip platform. As a proof-of-concept, we selected the fragments ALU115 and ALU247, recently identified as promising cancer targets in cfDNA integrity assessment. This work reveals a rational optimization of the DNA probes design and density at the surface which allowed achieving specific target detection and increased inhibition of unspecific interactions, without the need for blocking agents. The developed strategy is adaptable for the detection of mutations, homologous or truncated sequences such as the case of ALU115 and ALU247, sequences that share great similarity. Upon optimization, the MR sensors detected a concentration of the ALU elements within the picomolar range, showing potential for cfDNA analysis in cancer diagnostics. © The Royal Society of Chemistry 2016.


Jolly P.,University of Bath | Damborsky P.,Slovak Academy of Sciences | Madaboosi N.,INESC MN Microsystems and Nanotechnologies | Soares R.R.G.,INESC MN Microsystems and Nanotechnologies | And 6 more authors.
Biosensors and Bioelectronics | Year: 2016

Two novel sandwich-based immunoassays for prostate cancer (PCa) diagnosis are reported, in which the primary antibody for capture is replaced by a DNA aptamer. The assays, which can be performed in parallel, were developed in a microfluidic device and tested for the detection of free Prostate Specific Antigen (fPSA). A secondary antibody (Aptamer-Antibody Assay) or a lectin (Aptamer-Lectin Assay) is used to quantify, by chemiluminescence, both the amount of fPSA and its glycosylation levels. The use of aptamers enables a more reliable, selective and controlled sensing of the analyte. The dual approach provides sensitive detection of fPSA along with selective fPSA glycoprofiling, which is of significant importance in the diagnosis and prognosis of PCa, as tumor progression is associated with changes in fPSA glycosylation. With these approaches, we can potentially detect 0.5. ng/mL of fPSA and 3. ng/mL of glycosylated fPSA using Sambucus nigra (SNA) lectin, both within the relevant clinical range. The approach can be applied to a wide range of biomarkers, thus providing a good alternative to standard antibody-based immunoassays with significant impact in medical diagnosis and prognosis. © 2015 Elsevier B.V.


PubMed | INESC MN Microsystems and Nanotechnologies, Slovak Academy of Sciences, University of Bath and University of Lisbon
Type: | Journal: Biosensors & bioelectronics | Year: 2016

Two novel sandwich-based immunoassays for prostate cancer (PCa) diagnosis are reported, in which the primary antibody for capture is replaced by a DNA aptamer. The assays, which can be performed in parallel, were developed in a microfluidic device and tested for the detection of free Prostate Specific Antigen (fPSA). A secondary antibody (Aptamer-Antibody Assay) or a lectin (Aptamer-Lectin Assay) is used to quantify, by chemiluminescence, both the amount of fPSA and its glycosylation levels. The use of aptamers enables a more reliable, selective and controlled sensing of the analyte. The dual approach provides sensitive detection of fPSA along with selective fPSA glycoprofiling, which is of significant importance in the diagnosis and prognosis of PCa, as tumor progression is associated with changes in fPSA glycosylation. With these approaches, we can potentially detect 0.5 ng/mL of fPSA and 3 ng/mL of glycosylated fPSA using Sambucus nigra (SNA) lectin, both within the relevant clinical range. The approach can be applied to a wide range of biomarkers, thus providing a good alternative to standard antibody-based immunoassays with significant impact in medical diagnosis and prognosis.

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