Chiral Discrimination Performance of a Monolithic CMOS Gas Sensor Microsystem

The performance of a single-chip, three-transducer CMOS gas sensor microsystem for the discrimination of chiral molecules is demonstrated. For the discrimination of enantiomers, such as methyl lactate and methyl 2-chloropropionate, an enantioselective coating based on a modified γ-cyclodextrin dissolved in a polysiloxane matrix was used. The entire system comprising micromechanical components, i.e., a mass-sensitive, calorimetric, and capacitive transducer, and all the required circuitry components as well as interface and communication units are integrated on a single chip. The three different transducers inherently provide complementary information on the target analyte such as its volatility, polarity, and sorption heat.