Joao Pedro Conde

Learn More
As a leading cause of cancer-related deaths in men globally, prostate cancer (PCa) demands immense attention for theranostic purposes. There is an increasing need for the development of rapid, sensitive, economical, miniaturized and multiplexable assays. Towards this goal, we present a systematic approach for the optimisation of a microfluidic sandwich(More)
Microfluidic technology has the potential to decrease the time of analysis and the quantity of sample and reactants required in immunoassays, together with the potential of achieving high sensitivity, multiplexing, and portability. A lab-on-a-chip system was developed and optimized using optical and fluorescence microscopy. Primary antibodies are adsorbed(More)
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(More)
A flat microdevice which incorporates a thin-film amorphous silicon (a-Si:H) photodetector with an upper layer of functionalized SiO2 is used to quantify the density of both immobilized and hybridized DNA oligonucleotides labeled with a fluorophore. The device is based on the photoconductivity of hydrogenated amorphous silicon in a coplanar electrode(More)
Single square voltage pulses applied to buried electrodes result in dramatic rate increases for (1) selective covalent bonding (immobilization) of single-stranded DNA (ssDNA) probes to a functionalized thin film SiO(2) surface on a plastic substrate and (2) hybridization of ssDNA to the immobilized probe. DNA immobilization and hybridization times are 100(More)
Microfluidics and miniaturization of biosensors are fundamental for the development of point-of-care (PoC) diagnostic and analytical tools with the potential of decreasing reagent consumption and time of analysis while increasing portability. However, interfacing microfluidics with fluid control systems is still a limiting factor in practical(More)
Single, square voltage pulses in the microsecond timescale result in selective 5'-end covalent bonding (immobilization) of thiolated single-stranded (ss) DNA probes to a modified silicon dioxide flat surface and in specific hybridization of ssDNA targets to the immobilized probe. Immobilization and hybridization rates using microsecond voltage pulses at or(More)
Amorphous silicon-based ion-sensitive field-effect transistors (a-Si:H ISFETs) are used for the label-free detection of biological molecules. The covalent immobilization of DNA, followed by DNA hybridization, and of the surface adsorption of oligonucleotides and proteins were detected electronically by the a-Si:H ISFET. The ISFET measurements are performed(More)
The spatial and temporal control of biological species is essential in complex microfluidic biosystems. In addition, if the biological species is a cell, microfluidic handling must ensure that the cell's metabolic viability is maintained. The use of DEP for cell manipulation in microfluidics has many advantages because it is remote and fast, and the(More)
Parkinson's disease (PD) is a common age-associated neurodegenerative disorder. The protein α-synuclein (aSyn) is a key factor in PD both due to its association with familial and sporadic cases and because it is the main component of the pathological protein aggregates known as Lewy bodies. However, the precise cellular effects of aSyn aggregation are still(More)