Screen-printed electrochemical hybridization biosensor for the detection of DNA sequences from the Escherichia coli pathogen |
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| Authors: | Joseph Wang Gustavo Rivas Xiaohua Cai |
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| Affiliation: | 1. Departamento Físico Química, Universidad Nacional de Córdoba, 5016 Córdoba, Argentina Departamento Físico Química, Universidad Nacional de Córdoba, 5016 Córdoba, Argentina;2. Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA |
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| Abstract: | An electrochemical biosensor for the specific detection of short DNA sequences from the E. coli pathogen is described. This hybridization device relies on the immobilization of a 25-mer oligonucleotide probe, from the E. coli lacZ gene, onto a screen-printed carbon electrode. Chronopotentiometric detection of the Co(bpy)3+3 indicator is used for monitoring the hybridization event. Numerous variables of the assay protocol, including those of the probe immobilization step, the hybridization event, and the indicator association/detection, are characterized and optimized. Hybridization times of 2- and 30-min are sufficient for detecting 300- and 50 ng/mL, respectively, of the E. coli DNA target. Applicability to analysis of untreated environmental water samples is illustrated. Such single-use electrochemical sensors hold great promise for decentralized environmental and food testing for the E. coli pathogen. |
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| Keywords: | DNA biosensor Escherichia coli Bacteria Water quality Sequence-specific detection Hybridization Environmental monitoring Screen-printed electrode |
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