Palladium encapsulated mesoporous silica nanoparticles for the rapid detection of analytes.

We designed a simple, inexpensive, and user-friendly assay using mesoporous silica nanoparticles to detect analytes. Highly stable and uniform palladium nanoparticles covered with mesoporous silica (Pd@mSiO2) were generated and characterized extensively using physical methods. Human Serum Albumin (HSA) protein or ssDNA specific to the HIV gag region was capped onto the Pd@mSiO2 electrostatically. This “cap” prevented the Pd(0) inside the mesoporous silica nanoparticles from catalyzing the conversion of non-fluorescent molecules to fluorescent molecules. In the presence of target anti-HSA antibodies or complementary sequence (HIV gag), HSA protein or DNA cap dissociated from the surface of Pd@mSiO2-NH2 through the specific antigen–antibody reaction or DNA hybridization, allowing Pd(0) to convert the non-fluorescent molecules to fluorescent molecules. The limit and range of detection of anti-HSA antibodies were 3.8 nM and 3.8 nM to 133.3 nM, respectively. The limit and range of detection of HIV gag were 1.6 nM and 1.6 nM to 15 nM, respectively. This simple, inexpensive, “add sample and measure” diagnostic assay could potentially be incorporated into point of care diagnostics for lowresource settings.

我们利用介孔二氧化硅纳米粒子设计了一种简单、廉价且用户友好的检测分析物的方法。制备了被介孔二氧化硅覆盖的高度稳定且均匀的钯纳米粒子（Pd@mSiO₂），并使用物理方法对其进行了广泛的表征。将人血清白蛋白（HSA）蛋白或针对HIV gag区的单链DNA通过静电作用覆盖在Pd@mSiO₂上。这种“盖子”阻止了介孔二氧化硅纳米粒子内部的Pd(0)催化非荧光分子转化为荧光分子。在存在目标抗 - HSA抗体或互补序列（HIV gag）时，HSA蛋白或DNA盖子通过特异性抗原 - 抗体反应或DNA杂交从Pd@mSiO₂ - NH₂表面解离，使得Pd(0)能够将非荧光分子转化为荧光分子。抗 - HSA抗体的检测限和检测范围分别为3.8 nM和3.8 nM至133.3 nM。HIV gag的检测限和检测范围分别为1.6 nM和1.6 nM至15 nM。这种简单、廉价的“加入样品并测量”的诊断方法有可能被纳入资源匮乏地区的即时诊断中。