金标试纸条的三聚氰胺定量检测仪的研制

为了实现对乳制品中三聚氰胺的快速定量检测,研制了一种基于CMOS图像传感器的便携式金标试纸条定量检测仪.依据纳米金颗粒的吸收峰波长及CMOS器件的光谱响应,选择绿光LED作为系统照明光源,通过CMOS采集试纸条反应区域的光强分布得到检测带吸收特征峰曲线.利用特定算法对图像原始数据进行处理,从而有效降低了由于光电、生化和外界因素对系统检测的影响.建立被检测物浓度与检测带曲线特征值的函数关系用以确定样品中目标被测物的浓度.使用该金标检测仪对滴加有三聚氰胺标准样品的金标试纸条进行检测,在质量浓度为10⁵00ng/mL范围内具有良好的线性响应特性,相关系数R2>0.92.对同一金标试纸条各进行10次重复测量,变异系数小于2.5%,说明仪器具有响应快、高灵敏、便携等特点.

Development of melamine quantitative detection instrument based on colloidal gold strip

In order to realize the rapid quantitative detection of melamine in dairy products,a colloidal gold test strip reader based on the CMOS image sensor was developed.According to the wavelength of the absorption peak and the response of the CMOS device,we chose green LED as the light source The light intensity distribution of the strip reaction area was sampled by CMOS to acquire the curve of the absorption peak of the test line.The original image data were processed by a specific algorithm,which effectively reduced the influence of the photoelectric,biochemical and external factors of the system detection.The functional relationship between the feature information and the sample concentration was established to realize accurate measurement.Test results to strips of melamine with standard concentration gradients from 10 ng/mL to 500 ng/mL indicated that there was good linear response property.The correlation of coefficient（R2） was more than 0.92.The coefficient of variation of 10 times repetitive experiments of the same strip was less than 2.5 %.In conclusion,the developed apparatus has good performances such as rapid response,high sensitivity and portability.