Portable wide field fluorimeter systems

A portable system for detecting a change in fluorescence intensity in a liquid sample, the system comprising:

• a microfluidic device comprising:
• a housing comprising:
• an inlet that receives a liquid sample;
• an outlet for receiving the liquid sample from the inlet;
• a filter arranged between the inlet and the outlet and located to retain a target analyte;
• and
• a fluidic circuit arranged within the housing and comprising:
• a first channel in fluid communication with the inlet, wherein the first channel extends from the inlet to a first surface of the filter;
• and
• a second channel in fluid communication with the outlet, wherein the second channel extends from a second surface of the filter that is opposite to the first surface of the filter to the outlet, and is shaped and dimensioned to collect the liquid sample that has passed through the filter and has a depth that reduces an amount of unreacted detection reagent available to create background fluorescence during detection of the target analyte;
• an optical assembly comprising:
• an emission filter;
• a tube lens with a numerical aperture approximately equal to 0.4 and a focal length approximately equal to 3.3 millimeters;
• and
• an objective lens with a numerical aperture approximately equal to 0.79, a focal length approximately equal to 16 millimeters, and is coated with a 350 to 700 nanometer antireflective coating;
• an analyzer device configured to collect and process a fluorescent signal for the detection of the target analyte produced by a target pathogen, if present, in the liquid sample;
• one or more interface electronics;
• and
• a control circuit connected to an external interface of the analyzer device and configured to transmit control signals to the one or more interface electronics, wherein the analyzer device is configured to transmit signals to the control circuit through the external interface of the analyzer device.