表面等离子体共振(surface plasmon resonance,SPR)谱因共振强度、共振位置等不同而呈现不同的幅度和峰宽,需要发展自适应的分析方法才能保证SPR共振峰的精确定位.提出了一种基于Savitzky-Golay滤波器最优参数的SPR谱滤波方法,可根据实时SPR谱的特点优化滤波器参数(拟合阶数和窗宽),使滤波后光谱的均方误差(mean squared error,MSE)的Stein’s无偏风险估计(Stein’s unbiased risk estimate,SURE)最小,采用Monte-Carlo算法实现了SURE的快速求解.经验证,在不同的噪声水平下,SURE都可以准确反映实际MSE趋势及结果.采用搭建的SPR系统,实验测量了不同浓度、不同积分时间下蔗糖溶液的SPR信号,用提出的最优参数对SPR信号进行滤波,结果表明,与固定参数相比,该方法确定的SPR共振峰位置重复性误差较小,且不随噪声的增大而增大.

The spectrum of surface plasmon resonance shows different amplitudes and peak widths with the effects of resonant intensity and position,so it’s necessary to develop the self-adaptive methods to guarantee the accurate positioning of SPR formant.Based on the optimized Savitzky-Golay filter,this paper presents a method for SPR spectrum,which can optimize the parameters (polynomial degree and window size) according to the characteristics of the real time SPR spectrum,and minimizes the Stein’s unbiased risk estimate of the mean squared error,and it can be quickly solved by Monte-Carlo methods.It is confirmed that SURE can accurately reflect the trends and the results of the true MSE.The experiment measures the SPR signals of sucrose under different concentrations and integration time through the SPR system.By using the proposed method of optimal parameters on the SPR signal filtering,the results show that the repeatability error of the position of SPR formant is smaller compared with the fixed parameters,and does not increase with the addition of noise levels.