Continuous flow micro-cell for electrochemical addressing of engineered bio-molecules

Abstract A micro-cell consisting of a planar array of Au working electrodes, covered by a glass reservoir (600 nl capacity), connected with perpendicular capillaries and provided with an Ag/AgCl wire reference electrode (RE) has been manufactured. Addressed on-chip immobilization and sensing of biomolecules was demonstrated by the immobilization of histidine (HIS) tagged alkaline phosphatase (AP) under continuous flow (10 l/min) conditions on the base of electrochemically deposited multilayer (EDM) of cysteamine modified by nitrilotriacetic acid (NTA). The presented method allows the immobilization of different biomolecules on the ready-to-use reservoir covered chip without needs of manual biomolecule deposition. Further on, the detection of analytes can be performed using the electrochemical measurements. Since the methods of biomolecule deposition and sensing are both electrochemical, this allows simplifying the production technology using cheaper detection instruments compared to prevailing present-day optical detection modes

Developing a miniaturized continuous flow electrochemical cell for biosensor applications

ABSTRACT The development of a miniaturized electrochemical cell for biosensor application regards both the structuring of an array of electrodes in a fluidic chamber and their connections to the control & processing unit The sensitivity of the chronoamperometric measurement performed with the cell is increased by: (a) integrating the reference electrode on the same chip with the counter-and working-electrodes, (b) designing a specific pattern of the gold electrodes and (c) serially distributing them along the pipeline reservoir. Borosilicate glass is used as substrate for the electrodes, allowing, due to its transparency, an accurate and easy pad to pad alignment of the up-side-down chip versus a PCB soldered on a standard DIL 40 socket. This alignment is necessary to accomplish the elastomer-based-solderless electric contact, between chip and PCB. The solderless contact significantly improves both reliability and signal processing accuracy. The reservoir and its cover are micromachined out of silicone rubber respectively photosensitive glass in order to easy disassemble the fluidic chamber without any damage. Both thickness and elasticity of the photosensitive glass rend the device less brittle. A plug-in -plug-flow device with improved characteristics has been obtained with a modular structure that allows further extension of the number of electrodes

Exercise speckle-tracking strain imaging demonstrates impaired right ventricular contractile reserve in hypertrophic cardiomyopathy

Aims To analyse right ventricular (RV) systolic function in patients with hypertrophic cardiomyopathy (HCM) at rest and during exercise, and its possible correlation with left ventricular(LV) morphology and function.Methods and results: Standard echo, exercise stress echo, and RV 2D speckle-tracking strain (2DSE) were performed in 45 patients with HCM and in 45 age- and sex-comparable healthy controls. RV global longitudinal strain (GLS) was calculated by averaging local strains along the entire right ventricle. LV mass index and WS wall thickness were significantly increased in HCM, while LV ejection fraction, RV diameters, RV tissue Doppler systolic peak and the RV end-systolic pressure-area relationship at rest were comparable between the two groups. Conversely, all transmittal Doppler indexes were significantly impaired in HCM. In addition, RV GLS and regional peak myocardial RV strains were significantly reduced in patients with HCM (all P<0.001). During physical effort, LV ejection fraction was comparable between the two groups. Conversely, LV E/E-m, ratio was significantly increased in HCM. Increase in TAPSE and RV tissue Doppler Sm peak velocity during effort were similar between the two groups. Conversely, increases of RV end-systolic pressure-area, regional and global RV strain were significantly lower in HCM patients (RV lateral strain: 10.3 +/- 3.5% of increase in HCM vs 20.5 +/- 4.5% in controls; p < 0.0001). Multivariable analysis detected independent associations of RV lateral strain at peak stress with LV IVS thickness, maximal workload during exercise, and LV E/Er, ratio during effort (all p < 0.0001). An RV lateral 2DSE cut-off point of -14% differentiated controls and HCM with an 86%sensitivity and a 92% specificity.Conclusions: RV contractile reserve for HCM is impaired and this suggests that the lower resting values of RV in HCM may represent early subclinical myocardial damage, closely associated with exercise capacity. (C) 2016 Elsevier Ireland Ltd. All rights reserved