System for portable and easy-to-use detection of analytes with mobile computing device

A method for identifying a presence, absence, and/or quantity of a molecule of interest in a sample, the method comprising:

• localizing signaling enzymes over an electrochemical sensor within a cartridge, the signaling enzymes being from a fluid mixture comprising the sample collected by a sample collection device introduced into the cartridge, wherein the signaling enzymes are comprised within magnetic particle complexes;
• reacting the signaling enzymes localized over the electrochemical sensor with chemical substrates at the electrochemical sensor such that the signaling enzymes localized over the electrochemical sensor strip electrons from the chemical substrates;
• and
• sensing the reactions by the electrochemical sensor to identify the presence, absence, and/or quantity of the molecule of interest in the sample.