Optimisation of flow path parameters for enhanced sensitivity lateral flow devices

Lateral flow devices (LFDs) are widely used point-of-care (POC) diagnostics. The basic LFD design remains largely unchanged since their first development and this limits their use in clinical applications due to lack of sensitivity. To enhance this, we report the use of laser-patterned geometric control barriers, in the form of a constriction, that leads to a slower flow rate and smaller test zone area. This high sensitivity LFD (HS-LFD) achieved 62% increase in test line colour intensity for the detection of procalcitonin (PCT) and reduced the LOD from 10 ng/ml to 1 ng/ml with contrived human samples