光寻址电位传感器系统光源选定与设计

针对光寻址电位传感器光源的要求,在理论上从半导体的光学特性出发对光源进行了分析,讨论了照射光源的要求和中心波长及器件的确定,设计了寻址光源驱动电路及光路,经过实际使用,实现了激发光束的照射。

叶绿素a二水多聚体电极的光电效应

从鲜菠菜叶中提取叶绿素,用糖柱分离得纯叶绿素 a,再用水处理制得叶绿素 a 二水多聚体.并对其光谱特性进行了研究.用铺展法和电沉积法制得叶绿素电极.测量了其光感电位.研究了叶绿素 a 二水多聚体对光感电位的影响.结果表明,叶绿素 a 二水多聚体能在异辛烷溶液中用电沉积法制成叶绿素电极.

A non-labeled DNA biosensor based on light addressable potentiometric sensor modified with TiO_2 thin film

Titanium dioxide (TiO2) thin film was deposited on the surface of the light addressable potentiometric sensor (LAPS) to modify the sensor surface for the non-labeled detection of DNA molecules. To evaluate the effect of ultraviolet (UV) treatment on the silanization level of TiO2 thin film by 3-aminopropyltriethoxysilane (APTS),fluorescein isothiocyanate (FITC) was used to label the amine group on the end of APTS immobilized onto the TiO2 thin film. We found that,with UV irradiation,the silanization level of the irradiated area of the TiO2 film was improved compared with the non-irradiated area under well-controlled conditions. This result indicates that TiO2 can act as a coating material on the biosensor surface to improve the effect and efficiency of the covalent immobilization of biomolecules on the sensor surface. The artificially synthesized probe DNA molecules were covalently linked onto the surface of TiO2 film. The hybridization of probe DNA and target DNA was monitored by the recording of I-V curves that shift along the voltage axis during the process of reaction. A significant LAPS signal can be detected at 10 μmol/L of target DNA sample.

An on-chip electroosmotic micropump with a light-addressable potentiometric sensor

An on-chip electroosmotic(EO) micropump(EOP) was integrated in a microfluidic channel combined with a light-addressable potentiometric sensor(LAPS). The movement of EO flow towards right and left directions can be clearly observed in the microfluidic channel. The characteristics of photocurrent-time and photocurrent-bias voltage are obtained when buffer solution passes through the sensing region. The results demonstrate that the combination of an on-chip EOP with an LAPS is feasible.

Response enhancement of olfactory sensory neurons-based biosensors for odorant detection

This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor of phosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).

Research on the enhancement of signal-to-noise ratio of light-addressable potentiometric sensor by optical focusing

For enhancing the response of light-addressable potentiometric sensor(LAPS) and further improving its signal-to-noise ratio(SNR),an optical focusing method is adopted.Experimental research and theoretical analysis reveal that the magnitude of responsive signal is increased by optical focusing,and the SNR is improved remarkably.These research results indicate that the optical focusing is an effective approach for improving SNR of LAPS.