Fig. 1: Schematic diagram of the human exhaled gas diagnostic process.

Schematic diagram of the process of diagnosing diseases by sensing constituent chemical vapors of exhaled breath through a multiplexed DNA-functionalized graphene sensor and identifying gases through artificial intelligence. NH₃, NO, NO₂, and H₂S molecules that exist individually or in mixed states in exhaled human breath (under conditions of considerable humidity) are detected by the gas sensor array to which the DNA sequence is applied; the presence of these molecules is conveyed through an electrical signal. Their identification is achieved through artificial intelligence via feature selection, support vector machine (SVM), and 1D CNN for the diagnosis of lung and liver diseases. Adapted with permission^42,43