Design and Implementation of Ultra-micro Nucleic Acid Protein Analyzer / 中国医疗器械杂志

In this paper, a nucleic acid protein analyzer based on Lambert-Beer law and ultraviolet spectrophotometry is introduced, which is composed of ultraviolet monochromatic light generator, photoelectric signal detection module, vortex mixer, touch screen and embedded central controller. For ultra-micro measurement, a continuous-wavelength full-spectrum spectrophotometric detection circuit is designed in the hardware part. The transmitted light signal is collected by silicon photodiode, amplified and processed by subsequent circuit, and then transmitted to a single chip computer STM32F407VGT6 with CortexTM-M4 core after A/D conversion. The concentration and purity of nucleic acid protein are evaluated by assistant software detection algorithm. The instrument has the characteristics of compact size, flexible use, simple operation, high sensitivity and high detection efficiency. The experimental results show that the instrument has good sensitivity, repeatability and accuracy, and is suitable for the ultra-micro measurement of nucleic acid sample concentration, purity and protein concentration.

A Photoelecteochemical Sensor Based on CdS Sensitized Fe:TiO2Nanosheets for Determination of Cu2+ / 分析化学

Iron-doped titanium dioxide nanosheets was prepared by hydrothermal method using tetrabutyl titanate (C16H36O4Ti) and iron trifluoride (FeF3) and modified on ITO electrode.ITO/Fe : TiO2/CdS photoelectrochemical sensor was fabricated by successive ionic layer absorption and reaction(SILAR) method for determination of copper ion.The band gap of electode material was narrowed by iron doped TiO2 nanosheets,which made its absorption red-shifted and its response range of light was magnified.Based on the sensitization effect of CdS,the absorption and utilization of visible light of sensor was significantly enhanced and the photoelectric signal was amplified via reducing the recombination of electrons and holes.The sensor displayed excellent analytical performance for detection of copper ion with linear range of 0.2-4.0 μmol/L and 4.0-80.0 μmol/L and with the detection limit of 85 nmol/L.The sensor was used to detect copper ion in tap water,drinking water and Yongjiang river water with recoveries ranging from 94% to 111%.