AC and phase sensing of nanowires for biosensing

Silicon nanowires are label-free sensors that allow real-time measurements. They are economical and pave the road for point-of-care applications but require complex readout and skilled personnel. We propose a new model and technique for sensing nanowire sensors using alternating currents (AC) to capture both magnitude and phase information from the sensor. This approach combines the advantages of complex impedance spectroscopy with the noise reduction performances of lock-in techniques. Experimental results show how modifications of the sensors with different surface chemistries lead to the same direct-current (DC) response but can be discerned using the AC approach

On-Chip Sandwich Immunoassay in an Integrated Magneto-Optical CMOS Microsystem

We report on an innovative approach to on-chip detection of single fluorescently-labeled magnetic micro-particles by means of Single Photon Avalanche Diode (SPAD) arrays. Our system enables particle separation through magnetic actuation and highly sensitive, high signal-to-noise-ratio detection with integrated SPADs. We will present the capability of our system to detect and quantitatively distinguish fluorescently labeled particles. This represents a first step towards a complete lab-on-a-chip system for specific antibody detection. The selection of magnetic micro-particles as the mobile substrate in a bio-assay is motivated by their growing impact on the lab-on-a-chip research area, fueled by their ability of contactless manipulation and a handling that is independent from biological processes

AC and phase sensing of nanowires for biosensing

Data supporting the paper &quot;Crescentini, Marco, Rossi, Michele, Ashburn, Peter, Lombardini, Marta, Sangiorgi, Enrico, Morgan, Hywel and Tartagni, Marco (2016) AC and phase sensing of nanowires for biosensing. Biosensors, 6, (2), 1-14. (doi:10.3390/bios6020015)&quot;</span

Lung deposition of surfactant delivered via a dedicated laryngeal mask airway in piglets

It is unknown if the lung deposition of surfactant administered via a catheter placed through a laryngeal mask airway (LMA) is equivalent to that obtained by bolus instillation through an endotracheal tube. We compare the lung deposition of surfactant delivered via two types of LMA with the standard technique of endotracheal instillation. 25 newborn piglets on continuous positive airway pressure support (CPAP) were randomized into three groups: 1—LMA-camera (integrated camera and catheter channel; catheter tip below vocal cords), 2—LMA-standard (no camera, no channel; catheter tip above the glottis), 3—InSurE (Intubation, Surfactant administration, Extubation; catheter tip below end of endotracheal tube). All animals received 100 mg·kg−1 of poractant alfa mixed with99mTechnetium-nanocolloid. Surfactant deposition was measured by gamma scintigraphy as a percentage of the administered dose. The median (range) total lung surfactant deposition was 68% (10–85), 41% (5–88), and 88% (67–92) in LMA-camera, LMA-standard, and InSurE, respectively, which was higher (p < 0.05) in the latter. The deposition in the stomach and nasopharynx was higher with the LMA-standard. The surfactant deposition via an LMA was lower than that obtained with InSurE. Although not statistically significant, introducing the catheter below the vocal cords under visual control with an integrated camera improved surfactant LMA delivery by 65%

Thin film polycrystalline silicon nanowire biosensors

Polysilicon nanowire biosensors have been fabricated using a top-down process and were used to determine the binding constant of two inflammatory biomarkers. A very low cost nanofabrication process was developed, based on simple and mature photolithography, thin film technology and plasma etching, enabling an easy route to mass manufacture. Antibodyfunctionalized nanowire sensors were used to detect the proteins interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) over a wide range of concentrations, demonstrating excellent sensitivity and selectivity, exemplified by a detection sensitivity of 10fM in the presence of a 100,000-fold excess of a non-target protein. Nanowire titration curves gave antibody-antigen dissociation constants in good agreement with low-salt enzyme-linked immunosorbent assays (ELISAs). This fabrication process produces high-quality nanowires that are suitable for lowcost mass production, providing a realistic route to the realization of disposable nanoelectronic Point-of-Care (PoC) devices