为实现肠炎沙门菌的快速定量分析,采用Tris辅助柠檬酸钠还原法制备新型胶体金并利用Au-S配位作用在纳米金球表面修饰一层4-巯基苯甲酸(4-MBA)拉曼信号分子,然后以此为标记材料建立肠炎沙门菌表面增强拉曼(surface-enhancement of Raman ...为实现肠炎沙门菌的快速定量分析,采用Tris辅助柠檬酸钠还原法制备新型胶体金并利用Au-S配位作用在纳米金球表面修饰一层4-巯基苯甲酸(4-MBA)拉曼信号分子,然后以此为标记材料建立肠炎沙门菌表面增强拉曼(surface-enhancement of Raman scattering,SERS)免疫层析检测技术,并对其灵敏度、特异性和重复性进行考察。结果表明:建立的SERS免疫层析技术对肠炎沙门菌的可视化最低检测限(LOD)为10^(6) CFU/mL,而通过拉曼信号检测时LOD为10^(5) CFU/mL,灵敏度比裸眼观察提高了10倍。在10^(5)~10^(8) CFU/mL的浓度范围可根据标准曲线y=30.23×exp(-x/-147)-215.83(R^(2)=0.995)对肠炎沙门菌进行定量分析。该SERS免疫层析技术与鼠伤寒沙门菌、鸡白痢沙门菌、甲型副伤寒沙门菌等多种血清型沙门菌和大肠杆菌、副溶血弧菌等常见病原无交叉反应,特异性良好。同一批次的不同试纸条和不同批次的试纸条对相同样品的检测结果基本一致,重复性良好。以粪便和鸡蛋壳为基质的加标试验回收率在94.7%~104.9%之间,回收率良好。结果表明,基于金纳米颗粒的肠炎沙门菌SERS免疫层析快速检测技术灵敏度较高,特异性强,重复性好,能弥补传统胶体金试纸条无法定量的不足,可用于肠炎沙门菌的快速定量检测。展开更多
The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic sur...The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their industrialization.To address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in air.Through precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)sensors.The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energyenhancement.When the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering signal.This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)M.Notably,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of chemicals.Moreover,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS devices.Our study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy enhancement.The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,photovoltaics,and clean water,propelling us closer to a sustainable and cleaner future.展开更多
文摘由于宫颈细胞样本的液基薄层细胞学检测(thin prep cytologic test,TCT)图像内容复杂,背景颜色丰富多样,而且不同女性的宫颈细胞具有一定程度的天然差异,这给宫颈异常细胞的检测带来了很大的困难。为解决这一难题,提出了一种名为基于特征压缩与激发和可变形卷积(SE-ResNet-deformable convolution you only look once,SER-DC YOLO)的目标检测网络。该网络在YOLOv5的Backbone中融合注意力机制,添加了SE-ResNet模块,然后改进了SPP层的网络结构,并且使用可变形卷积来替换普通卷积,最后修改了边界框的损失计算函数,将广义交并比(generalized intersection over union,GIoU)改为α-IOU Loss。实验表明,该网络与YOLOv5网络相比,在宫颈图片数据集上召回率提高了19.94%,精度提高了3.52%,平均精度均值提高了7.19%。相关代码链接:https://github.com/sleepLion99/SER-DC_YOLO。
基金the support by the Office of Naval Research’s NEPTUNE Program under the Grant Number N00014-16-1-3109the National Science Foundation CMMI NanoManufacturing Program。
文摘The remarkable capabilities of 2D plasmonic surfaces in controlling optical waves havegarnered significant attention.However,the challenge of large-scale manufacturing of uniform,well-aligned,and tunable plasmonic surfaces has hindered their industrialization.To address this,we present a groundbreaking tunable plasmonic platform design achieved throughmagnetic field(MF)assisted ultrafast laser direct deposition in air.Through precise control of metal nanoparticles(NPs),with cobalt(Co)serving as the model material,employing an MF,and fine-tuning ultrafast laser parameters,we have effectively converted coarse and non-uniform NPs into densely packed,uniform,and ultrafine NPs(~3 nm).This revolutionary advancement results in the creation of customizable plasmonic‘hot spots,’which play a pivotal role insurface-enhanced Raman spectroscopy(SERS)sensors.The profound impact of this designable plasmonic platform lies in its close association with plasmonic resonance and energyenhancement.When the plasmonic nanostructures resonate with incident light,they generate intense local electromagnetic fields,thus vastly increasing the Raman scattering signal.This enhancement leads to an outstanding 2–18 fold boost in SERS performance and unparalleled sensing sensitivity down to 10^(-10)M.Notably,the plasmonic platform also demonstratesrobustness,retaining its sensing capability even after undergoing 50 cycles of rinsing andre-loading of chemicals.Moreover,this work adheres to green manufacturing standards,making it an efficient and environmentally friendly method for customizing plasmonic‘hot spots’inSERS devices.Our study not only achieves the formation of high-density,uniform,and ultrafine NP arrays on a tunable plasmonic platform but also showcases the profound relation betweenplasmonic resonance and energy enhancement.The outstanding results observed in SERS sensors further emphasize the immense potential of this technology for energy-relatedapplications,including photocatalysis,photovoltaics,and clean water,propelling us closer to a sustainable and cleaner future.