Device and methods for detecting pathogens

A method for predicting the presence of at least one microbe of interest executable by at least one processor, the method comprises the steps:

• receiving a plurality of capacitance signals generated by a plurality of capacitive sensors in response to exposure thereof to a sample, wherein the plurality of capacitive sensors comprises at least a first sensor, a second sensor and a third sensor;
• introducing the plurality of capacitance signals to machine-learning (ML) model, wherein said ML model is trained to predict a presence and a concentration of a microbe of interest within the gaseous sample based on said capacitance signals;
• and producing an indication of presence or of a concentration of the microbe of interest within the sample based on the prediction;
• wherein:
• each of the plurality of capacitive sensors comprises a sensing element electrically connected to at least two electrodes and comprises carbon dots;
• the carbon dots comprise hydrophilic surface groups, comprising nitrogen and oxygen atoms;
• wherein a nitrogen content of the carbon dots of the first sensor, the second sensor and of the third sensor is between 13 and 20 at %, between 10 and 12.9 at %, and between 1 and 9.9 at %, respectively;
• the plurality of capacitive sensors comprises carbon dots characterized by different polarity;
• the hydrophilic surface groups of the carbon dots predetermine:
• (i) a different surface polarity;
• and (ii) a different sensitivity of the plurality of capacitive sensors to a specific VC.