Reagentless Microsensor Based on Conducting Poly(3-aminophenylboronic Acid) for Rapid Detection of Microorganisms in Aerosol

We report on microsensor for direct detection of microorganisms in aerosol. Microsensor is based on interdigitated ultramicroelectrodes modified with electropolymerized 3-aminophenylboronic acid (3-APBA). Appearance of Penicillium chrysogenum in aerosol as well as further increase of its concentration lead to poly(3APBA) conductivity increase found by impedance spectroscopy. According to Raman spectroscopy data, the presence of microorganism affects polymer conductivity similarly to binding of glucose to polymer which results in self-doping phenomenon. The elaborated detection technique is 100 times faster comparing to agar plate cultivation: it requires less than 20 minutes for analysis. Dynamic range of microsensor includes the upper limit for non-contaminated air in Russian hygienic standard (500 colony-forming units per cubic meter). The first reported reagentless detection of Penicillium chrysogenum in aerosol by conductivity increase reveals a prospect for creation of a promising alternative to conventional techniques for detection of microorganisms.