Handheld fluorescence test strip reader for rapid on-site biochemical detection

Test strips have been widely used in various rapid on-site biochemical sensing due to its simple and rapid detections. Unfortunately, many test strips only support qualitative sensing mainly because their detecting results are often determined by visual inspection. In order to solve the problem, we design a handheld fluorescence test strip reader, which can collect fluorescence emission from test strip thus quantify target under detection. The proposed handheld fluorescence test strip reader composes of rather compact optical system including a light emitting diode (LED) for excitation, an optical bandpass filter for fluorescence signal filtering and a smartphone for fluorescence signal collection and data analysis. All the optical elements are integrated using 3-D printed structures and coupled with the smartphone to support on-site detection. In addition, a smartphone application is also designed to automatically quantify fluorescence emission intensity, and it definitely can support quantitative target detection. Proved by a series of applications especially on rapid on-site detections, the handheld fluorescence test strip reader can detect target automatically, rapidly and accurately. Therefore, the proposed handheld fluorescence test strip reader is a potential tool for rapid on-site biochemical detection in various applications including agricultural, biomedical, and environmental fields.