In this work,a very simple dual-readout lateral flow test strip(LFTS)platform was developed for sensitive detection of alkaline phosphatase(ALP)based on a portable device.In this assay,quantum dots(QDs)conjugated with...In this work,a very simple dual-readout lateral flow test strip(LFTS)platform was developed for sensitive detection of alkaline phosphatase(ALP)based on a portable device.In this assay,quantum dots(QDs)conjugated with bovine serum albumin(QDs-BSA)were chosen as fluorescence signal labels.In the absence of ALP,MnO_(2)nanosheets aggregate on the test line and exhibit an obvious brown color,which can be observed by naked eyes to realize semi-qualitative analysis.Meanwhile,fluorescence intensity of QDs-BSA can also be effectively quenched by MnO_(2)nanosheets due to inner-filter effect.Correspondingly,in the presence of ALP,ALP can catalyze the hydrolysis of ascorbic acid 2-phosphate(AAP)to generate L-ascorbic acid(AA),which can reduce MnO_(2)into Mn^(2+),accompanying with the obvious fluorescence recovery of the QDs.By simply monitoring the change of colorimetric and fluorescent signal on the test line,trace amount of ALP can be quantitatively detected.Under the optimal conditions,measurable evaluation of ALP was reached in a linear range from 1 U/L to 20 U/L with a detection limit of 0.7 U/L based on fluorescence signal.Furthermore,this colorimetric/fluorescent dual-readout assay was successfully applied to monitor ALP in human serum samples,showing its great potential as a point of care biosensor for clinical diagnosis.展开更多
轴向位置的精确测量是快中子探测领域的挑战和难题,对高分辨率的快中子成像具有重要意义。改进位置和时间响应能使快中子成像获得更好的成像分辨率和对比度,而提升时间分辨的困难主要来自相互作用深度(depth of interaction,DOI)的不确...轴向位置的精确测量是快中子探测领域的挑战和难题,对高分辨率的快中子成像具有重要意义。改进位置和时间响应能使快中子成像获得更好的成像分辨率和对比度,而提升时间分辨的困难主要来自相互作用深度(depth of interaction,DOI)的不确定性。针对位置改进的问题,设计了一种基于有机闪烁体阵列的双端读出快中子探测器,提出了一种用于校准DOI的方法。该校准方法基于快中子探测器双端读出的数据来进行系列计算和拟合,最终得到轴向位置校准曲线。研究结果表明,该校准方法解决了快中子探测中轴向定位不准确的问题,提高了快中子探测器的位置分辨率。展开更多
基金supported by the National Natural Science Foundation of China(Nos.21974125,21605038)the National 111 Project(No.D20003)+1 种基金the Collaborative Innovation Project of Zhengzhou(Zhengzhou University)(No.18XTZX12002)the Key Scientific Research Project in Universities of Henan Province(No.19A150048).
文摘In this work,a very simple dual-readout lateral flow test strip(LFTS)platform was developed for sensitive detection of alkaline phosphatase(ALP)based on a portable device.In this assay,quantum dots(QDs)conjugated with bovine serum albumin(QDs-BSA)were chosen as fluorescence signal labels.In the absence of ALP,MnO_(2)nanosheets aggregate on the test line and exhibit an obvious brown color,which can be observed by naked eyes to realize semi-qualitative analysis.Meanwhile,fluorescence intensity of QDs-BSA can also be effectively quenched by MnO_(2)nanosheets due to inner-filter effect.Correspondingly,in the presence of ALP,ALP can catalyze the hydrolysis of ascorbic acid 2-phosphate(AAP)to generate L-ascorbic acid(AA),which can reduce MnO_(2)into Mn^(2+),accompanying with the obvious fluorescence recovery of the QDs.By simply monitoring the change of colorimetric and fluorescent signal on the test line,trace amount of ALP can be quantitatively detected.Under the optimal conditions,measurable evaluation of ALP was reached in a linear range from 1 U/L to 20 U/L with a detection limit of 0.7 U/L based on fluorescence signal.Furthermore,this colorimetric/fluorescent dual-readout assay was successfully applied to monitor ALP in human serum samples,showing its great potential as a point of care biosensor for clinical diagnosis.
文摘轴向位置的精确测量是快中子探测领域的挑战和难题,对高分辨率的快中子成像具有重要意义。改进位置和时间响应能使快中子成像获得更好的成像分辨率和对比度,而提升时间分辨的困难主要来自相互作用深度(depth of interaction,DOI)的不确定性。针对位置改进的问题,设计了一种基于有机闪烁体阵列的双端读出快中子探测器,提出了一种用于校准DOI的方法。该校准方法基于快中子探测器双端读出的数据来进行系列计算和拟合,最终得到轴向位置校准曲线。研究结果表明,该校准方法解决了快中子探测中轴向定位不准确的问题,提高了快中子探测器的位置分辨率。
