Biosensors & bioelectronics
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Biosens Bioelectron · Apr 2007
Development of a self-sterilizing lancet coated with a titanium dioxide photocatalytic nano-layer for self-monitoring of blood glucose.
A photocatalyst was applied to a lancet for pricking the finger to obtain an antibacterial property. A photocatalytic and uniform nano-layer of titanium dioxide (TiO2) on the surface of the lancet (0.36 mm x 24.5 mm) was formed by sputtering and annealed for crystallization of the TiO2 layer. By elementary analysis of the TiO2 layer, titanium and oxygen were detected. ⋯ Finally, lancing resistances obtained by pricking an artificial skin sheet were examined using control lancets, and lancets with an unannealed TiO2 layer or an annealed TiO2 layer. The results showed almost the same lancing resistances for the control (0.53+/-0 N, n=3) and the lancet with an annealed TiO2 layer (0.51+/-0.018 N), while the lancet with an unannealed TiO2 layer showed a high lancing resistance compared with the other lancets (0.62+/-0.05 N). In conclusion, the lancet coated with a crystallized, velvety nano-layer of TiO2 obtained by annealing had antibacterial properties and a similar lancing resistance compared with the bare lancet, and showed potential for application in monitoring blood glucose in diabetes.
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Biosens Bioelectron · Feb 2007
Long-term recording on multi-electrode array reveals degraded inhibitory connection in neuronal network development.
Spontaneous neuronal activity plays an important role in development. However, the mechanism that underlies the long-term spontaneous developmental change of cultured neuronal networks in vitro is not well understood. To investigate the contribution of inhibitory and excitatory connections to the development of neuronal networks, dissociated neurons from an embryonic rat hippocampal formation were cultured on a multi-electrode array plate and spontaneous activities were recorded by multi-channel system. ⋯ Kynurenic acid, a broad-spectrum glutamate receptor antagonist, blocked all activities while CNQX inhibited only the local synchronized or random spikes. These suggest that the inhibitory connection was age-dependent degraded in vitro and the developmental spontaneous firing pattern was built by the homeostatic balance of the excitatory-inhibitory connection networks. Long-term cultures on MEA provided a useful tool to measure the relationship between spontaneous developmental change and pharmacological influence in vitro.
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Biosens Bioelectron · Jan 2007
A fuzzy expert system design for analysis of body sounds and design of an unique electronic stethoscope (development of HILSA kit).
In this paper we have developed a fuzzy expert system (FES) for different sounds produced by different organs in the human body. We have also constructed a unique electronic stethoscope. The human body sounds produced by different organs like heart, lungs and intestine were analyzed. ⋯ Such FES helps the medical doctor in arriving at appropriate decision in different difficult clinical situations. The examination of body sounds was done using conventional stethoscope (CS) and electronic stethoscope (ES), which was uniquely designed for this study. We have found that unique stethoscope developed by us is far superior to conventional stethoscope by its overall performance.
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Biosens Bioelectron · Dec 2006
Epoxy-silane linking of biomolecules is simple and effective for patterning neuronal cultures.
Surface chemistry is one of the main factors that contributes to the longevity and compliance of cell patterning. Two to three weeks are required for dissociated, embryonic rat neuronal cultures to mature to the point that they regularly produce spontaneous and evoked responses. Though proper surface chemistry can be achieved through the use of covalent protein attachment, often it is not maintainable for the time periods necessary to study neuronal growth. ⋯ Spontaneous neural activity was recorded as early as 10 days in vitro. Neural recording and stimulation were readily achieved from these networks. Our results showed that 3-GPS could be used on surfaces to immobilize biomolecules for a variety of neural engineering applications.
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Biosens Bioelectron · Aug 2006
Integration of a surface acoustic wave biosensor in a microfluidic polymer chip.
SAW devices based on horizontally polarized surface shear waves (HPSSW) enable label-free, sensitive and cost-effective detection of biomolecules in real time. It is known that small sampling volumes with low inner surface areas and minimal mechanical stress arising from sealing elements of miniaturized sampling chambers are important in this field. Here, we present a new approach to integrate SAW devices with sampling chamber. ⋯ The polymeric encapsulation was performed tailor-made by Rapid Micro Product Development 3Dimensional Chip-Size-Packaging (RMPD 3D-CSP), a 3D photopolymerisation process. The polymer housing serves as tight and durable package for HPSSW biosensors and allows the use of the complete chips as disposables. Preliminary experiments with these microfluidic chips are shown to characterise the performance for their future applications as generic bioanalytical micro devices.