Photoelectrochemical Strategy for Discrimination of Microbial Pathogens Using Conjugated Polymers

A photoelectrochemical (PEC) biosensor for facile and sensitive identification of pathogenic microorganisms was developed. Cationic poly(phenylene vinylene) derivative (PPV) as photoelectrochemical active species was modified on the electrode. Under light irradiation, PPV could be excited and generate efficient photocurrent. PPV also had the ability to bind with negatively charged membrane of pathogenic microorganisms, which hindered the electron transfer between electrode and electrolyte. As a result, the photocurrent would decrease obviously. For E. coli, B. subtilis and C. albicans, the photocurrent density was reduced by 18, 33 and 59 %, respectively. Based on the reduction degree of the photocurrent after capturing different types of species of pathogenic microorganisms, a PEC sensor for discrimination of pathogenic microorganisms was realized.