Electrocatalytic aptasensor for bacterial detection exploiting ferricyanide reduction by methylene blue on mixed PEG/aptamer monolayers

TY - JOUR

T1 - Electrocatalytic aptasensor for bacterial detection exploiting ferricyanide reduction by methylene blue on mixed PEG/aptamer monolayers

AU - Jamal, Rimsha B.

AU - Bay Gosewinkel, Ulrich

AU - Ferapontova, Elena E.

N1 - Publisher Copyright: © 2023 The Author(s)

PY - 2024/4

Y1 - 2024/4

N2 - Pathogen-triggered infections are the most severe global threat to human health, and to provide their timely treatment and prevention, robust methods for rapid and reliable identification of pathogenic microorganisms are required. Here, we have developed a fast and inexpensive electrocatalytic aptamer assay enabling specific and ultrasensitive detection of E. coli. E. coli, a biomarker of environmental contamination and infections, was captured on the mixed aptamer/thiolated PEG self-assembled monolayers formed on electrochemically pre-treated gold screen-printed electrodes (SPE). Signals from aptamer - E. coli binding were amplified by electrocatalytic reduction of ferricyanide mediated by methylene blue (MB) adsorbed on bacterial and aptamer surfaces. PEG operated as an antifouling agent and inhibited direct (not MB-mediated) discharge of ferricyanide. The assay allowed from 10 to 1000 CFU mL−1 E. coli detection in 30 min, with no interference from B. subtilis, in buffer and artificial urine samples. This electrocatalytic approach is fast, specific, sensitive, and can be used directly in in-field and point-of-care applications for analysis of bacteria in human environment.

AB - Pathogen-triggered infections are the most severe global threat to human health, and to provide their timely treatment and prevention, robust methods for rapid and reliable identification of pathogenic microorganisms are required. Here, we have developed a fast and inexpensive electrocatalytic aptamer assay enabling specific and ultrasensitive detection of E. coli. E. coli, a biomarker of environmental contamination and infections, was captured on the mixed aptamer/thiolated PEG self-assembled monolayers formed on electrochemically pre-treated gold screen-printed electrodes (SPE). Signals from aptamer - E. coli binding were amplified by electrocatalytic reduction of ferricyanide mediated by methylene blue (MB) adsorbed on bacterial and aptamer surfaces. PEG operated as an antifouling agent and inhibited direct (not MB-mediated) discharge of ferricyanide. The assay allowed from 10 to 1000 CFU mL−1 E. coli detection in 30 min, with no interference from B. subtilis, in buffer and artificial urine samples. This electrocatalytic approach is fast, specific, sensitive, and can be used directly in in-field and point-of-care applications for analysis of bacteria in human environment.

KW - Aptasensor

KW - Bacterial detection

KW - E. coli

KW - Electrocatalysis

KW - Ferricyanide

KW - Methylene blue

KW - Limit of Detection

KW - Ferricyanides

KW - Humans

KW - Escherichia coli

KW - Biosensing Techniques/methods

KW - Gold/chemistry

KW - Electrodes

KW - Methylene Blue/chemistry

KW - Electrochemical Techniques/methods

KW - Aptamers, Nucleotide/chemistry

U2 - 10.1016/j.bioelechem.2023.108620

DO - 10.1016/j.bioelechem.2023.108620

M3 - Journal article

C2 - 38006817

AN - SCOPUS:85178011190

SN - 1567-5394

VL - 156

JO - Bioelectrochemistry

JF - Bioelectrochemistry

M1 - 108620

ER -