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The surface morphology of lateral flow (LF) strip is examined by scanning electron microscope (SEM) and the diffuse reflection of porous strip with or without nanogold particles is investigated. Based on the scattering and absorption of nanogold particles, a reflectance photometer is developed for quantification of LF strip with nanogold particles as reporter. The integration of reflection optical density is to indicate the signals of test line and control line. As an example, serial dilutions of microalbunminuria (MAU) solution are used to calibrate the performance of the reflectance photometer. The dose response curve is fitted with a four-parameter logistic mathematical model for the determination of an unknown MAU concentration. The response curve spans a dynamic range of 5 to 200 µg/ml. The developed reflectance photometer can realize simple and quantitative detection of analyte on nanogold-labeled LF strip.

This work provides an integrated design and simulation method for a pupil shaping unit, which combines optical design and simulation software using the Python programming language. The novel approach presented here allows for systematic optimization and solves the inverse problem to obtain the configuration of a pupil shaping unit with given partial coherence factors (sigmas). The relationships among sigma, focal length, zoom lens separation, axicon separation, and ring width are investigated for conventional and annular illumination modes. Results of the pupil shaping unit for a NA 0.75 193 nm photolithography machine are presented, and a new interpolation table design method that simplifies the original method is proposed. The maximum residual experimental error for sigma is 0.01106.

Gold labeled immunochromatography assay is widely used in many fields. Quantitative test can be realized by using a reflectance photometer. However, theoretical analysis of the strip and the photometer has seldom been reported. In this paper, the microstructure of immunochromatographic strip labeled by nanogold particles is analyzed with scanning electron microscope (SEM). Based on the SEM images of the strip, Mie's scattering theory is used to investigate the scattering behaviors of particles in the strip, and Lambert cosine law is applied to analyze the diffuse reflection of porous strip. Besides, a reflectance photometer for gold labeled test strip has been developed for fast quantification of immunochromatography assay in our group. Theoretical model is achieved by introducing the parameter of the developed reflectance photometer. The calculated scattering signal distribution is well consistent with that measured by the reflectance photometer.

A novel biosensor based on up-converting phosphor technology (UPT) was developed several years ago. It is a kind of optical biosensor using up-converting phosphor (UCP) particles as the biological marker. From then on, some improvements have been made for this UPT-based biosensor.The primary aspects of the improvement lie in the control system. On one hand, the hardware of the control system has been optimized, including replacing two single chip microcomputers (SCM) with only one, the optimal design of the keyboard interface circuit and the liquid crystal module (LCM) control circuit et al.. These result in lower power consumption and higher reliability. On the other hand, a novel signal processing algorithm is proposed in this paper, which can improve the automation and operating simplicity of the UPT-based biosensor.It has proved to have high sensitivity (~ng/ml), high stability and good repeatability (CV<5%), which is better than the former system. It can meet the need of some various applications such as rapid immunoassay, chemical and biological detection and so on.