Label-free electrochemical sensor based on spore-imprinted polymer for Bacillus cereus spore detection

Herein, we report a simple, cost-effective, selective, and rapid electrochemical sensor for Bacillus cereus spore detection, used as simulant for Bacillus anthracis spores. The sensor was developed using carbon paste electrode functionalized with imprinted polymer, fabricated by pyrrole electropolymerization in presence of a known amount of spores as template onto the surface of working electrochemical sensor. The measurement encompasses the cyclic voltammetry as technique and [Fe(CN)6]3−/4− as redox probe for electrochemical measurements. The effect of ultrasonication and surfactants with positive, negative and neutral charge on template removal was investigated. Several parameters including the concentration of monomer, the number of scans, the type and the concentration of removal agent, and the incubation time were optimized. The carbon paste electrode modified with spore-imprinted polymer (CPE/SIP) exhibited a good affinity and selectivity towards Bacillus cereus spores. The sensitivity of the CPE/SIP was investigated in the spore concentration ranging from 102 up to 105 CFU/mL, demonstrating the suitability of this sensor for fast and effective measurements of Bacillus cereus spores.