preparation of electrochemical sensor based on 3-thiophene acetic acid molecularly imprinted polymer for detection of streptococcus pneumoniae

Abstract: streptococcus pneumoniae (sp) is one of the most common gram-positive bacteria human pathogens and a cause of including pink eye, meningitis and pneumonia, sinusitis, and otitis media. sometimes it infects tissues in other parts of the body therefore, the rapid and sensitive detection and measurement of this bacteria is vital. among various methods, electrochemical analyses, with label-free, are a promising technique because of their merits of being rapid, highly sensitive, and is widely used [1, 2]. s. pneumoniae -imprinted polymer-based sensor was prepared to detect s. pneumoniae by electropolymerization of 3-thiophene acetic acid on the gold electrode surface using the cyclic voltammetry method in the presence of s. pneumoniae as the template and 3-thiophene acetic acid as the functional monomer. after the removal of the bacterial template from the electrode surface, a series of cavities will be formed in the shape of the desired bacteria in the polymer structure [3]. to study the morphology of the desired bacterium and poly tpa, sem images of different polymer films modified electrodes were used during the process of bacterial imprinting and recognition. cv and eis techniques were used to characterize the imprinting process and dpv technique was introduced to draw a calibration graph under optimal conditions and for all of the electrochemical measurements. the selectivity of the proposed sensor was investigated by interfering bacteria. the high selectivity of the sensor against the template bacteria could be ascribed to its sensitivity to the chemical conformation of bacterial outer cell structures. the imprinted electrochemical sensor based on a surface-imprinted polymer-modified electrode was successfully applied to detect s. pneumoniae in human serum.