不同粒径的Au纳米粒子对SPR技术定量分析灵敏度的影响

目的通过比较不同粒径金纳米粒子（Au NPs）对表面等离子共振（surface plasmon resonance,SPR）系统信号放大的影响,筛选最适粒径的Au NPs,从而建立一种新的SPR方法用于猕猴血清中西妥昔单抗（C225）定量分析。方法利用柠檬酸还原HAuCl4法自行制备3种粒径Au NPs并分别与羊抗人IgG进行偶联,将偶联物引入BI-Acore系统进行SPR信号采集,筛选最适粒径的Au NPs,进而利用BIAcore系统建立猕猴体内C225定量分析标准曲线。结果自行制备的Au NPs形状相对圆润,大小均一。几种粒径的Au NPs均能引起SPR信号放大,但粒径不同则SPR信号放大情况不同,其中10 nm Au NPs的SPR信号放大作用最为明显。结论将特定大小的Au NPs引入SPR定量分析系统能够显著提高SPR信号强度,从而进一步提高SPR定量分析灵敏度。

Effect of Au NPs of different sizes on sensitivity of SPR-based quantification method

Objective To compare the signal enhancements by gold nanoparticles（Au NPs） of different sizes in surface plasmon resononce（SPR） system,to select Au NPs with the optimum diameter and to establish a new SPR-based method for quantifying cetuximab（C225） concentration in rhesus monkey serum.Methods Au NPs of three different diameters were self-assembly synthesized by reducing HAuCl4 using sodium citrate and conjugating with goat anti-human IgG,respectively.SPR signals were measured using BIAcore system.Au NPs of the optimum diameter were identified and the construct calibration curve was constructed using the BIAcore system with Au NPs for measuring C225 concentrations in monkey serum.Results The Au NPs yielded by the self-assembling method were relatively spherical and homogeneous.Au NPs of different sizes could cause SPR signal enhancement,but the enhancement level varied with the colloid diameter value.10 nm Au NPs exhibited the most significant signal enhancement in the SPR-based quantification course.Conclusion By combining Au NPs of specific sizes with SPR-based quantification system,the SPR signal enhancement is achieved,and the sensitivity of SPR-based quantification assay is improved.