Figure 2.

Inner assembly of the design of the UV fluorescence-based optical reader. (a) Exploded view of the optical reader. The fluorescence sensor excites the fluorescence signal with a 380 nm UV LED and captures the spectrum larger than 530 nm in wavelength with a long pass filter. The CMOS camera and the LED array are controlled by a Raspberry Pi inside the optical reader. The sensor holder and the Raspberry Pi are not shown in the figure for clarity. (b) CAD design for the UV fluorescence sensor coupled with other parts. (c) Assembly view of the UV fluorescence sensor coupled with other parts. (d) External view of the UV fluorescence-based optical reader with casing. The PCT/CRP duplex LFA assembled in a cassette is placed on the sliding tray. During the imaging process, the indicator light is turned on, and the tray is closed to remove the effect of external light. The picture of the LFA shows the UV fluorescence signal on the test strip for a co-detection case where the control line, PCT test line, and CRP test line all show up from top to bottom.