We report on the use of a laser-direct write (LDW) technique that allows the fabrication of lateral flow devices with enhanced sensitivity and limit of detection. This manufacturing technique comprises the dispensing of a liquid photopolymer at specific regions of a nitrocellulose membrane and its subsequent photopolymerisation to create impermeable walls inside the volume of the membrane. These polymerised structures are intentionally designed to create fluidic channels which are constricted over a specific length that spans the test zone within which the sample interacts with pre-deposited reagents. Experiments were conducted to show how these constrictions alter the fluid flow rate and the test zone area within the constricted channel geometries. The slower flow rate and smaller test zone area result in the increased sensitivity and lowered limit of detection for these devices. We have quantified these via the improved performance of a C-Reactive Protein (CRP) sandwich assay on our lateral flow devices with constricted flow paths which demonstrate an improvement in its sensitivity by 62x and in its limit of detection by 30x when compared to a standard lateral flow CRP device.

我们报告了激光直接写入（LDW）技术的使用，该技术允许制造具有增强的灵敏度和检测极限的侧向流动装置。这种制造技术包括在硝酸纤维素膜的特定区域分配液体光敏聚合物，并随后进行光聚合，以在膜的内部形成不可渗透的壁。这些聚合的结构被有意设计为产生流体通道，该通道在特定长度上受到限制，该特定长度跨越了样品与预沉积试剂相互作用的测试区域。进行实验以显示这些收缩如何改变流体流量以及收缩通道几何形状内的测试区域面积。较慢的流速和较小的测试区域会导致这些设备的灵敏度提高和检测极限降低。我们通过对流道狭窄的侧向流动装置进行C反应蛋白（CRP）夹心测定的性能改进来对这些物质进行量化，与标准品相比，其侧向流动装置的灵敏度提高了62倍，检出限提高了30倍横向流CRP装置。