Portable and simultaneous mass and optical food safety detection tool based on smartphone-based quartz crystal microbalance

A pathogen detection system, comprising:

• a microfluidic channel adapted to transfer a volume of fluid from a source to a destination, the destination defining a target;
• a micropump coupled to the microfluidic channel and configured to force fluid along the microfluidic channel from the source to the destination;
• a mass measurement subsystem adapted to measure changes in mass of a substance at the destination of at least 1 nanogram;
• a light excitation subsystem adapted to project light onto the target;
• an image capture subsystem adapted to monitor the target and obtain images therefrom;
• and
• a processing subsystem executing instructions held in a non-transitory memory, the processing subsystem adapted to:
• (i) operate the micropump to thereby force a first fluid hosting a pathogen-selective antibody from the source to the destination,
• (ii) operate the micropump to thereby force a second fluid potentially hosting the selective pathogen from the source to the destination,
• (iii) obtain a signal from the mass measurement subsystem indicating a mass change between steps (i) and (ii),
• (iv) compare the mass change to a predetermined threshold to indicate conditional presence of the pathogen and concentration of the pathogen,
• (v) operate the micropump to thereby force a third fluid hosting a pathogen-selective photoluminescent label from the source to the destination,
• (vi) activate the light excitation subsystem,
• (vii) capture one or more images from the target by the image capture subsystem, and
• (viii) analyze the captured one or more images to determine presence of the pathogen-selective photoluminescent label thus double-confirming a) presence of the pathogen, and b) concentration of the pathogen.