Molecularly imprinted polymer combined with MOF-assisted redox recycling amplification: A powerful electrochemical sensing strategy for pathogenic bacteria

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-07, Vol.410, p.135682, Article 135682
• Main Authors: Liu, Yang, Meng, Xian-Zhu, Luo, Xiao, Gu, Hui-Wen, Yin, Xiao-Li, Han, Wu-Li, Yi, Hong-Chao, Chen, Ying
• Format: Article
• Language: English
• Subjects: Electrochemical sensor; Metal-organic frameworks; Molecularly imprinted polymer; Sensitivity
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2024.135682

Rapid and sensitive determination of foodborne pathogenic bacteria at a low cost is crucial for ensuring food safety monitoring and diagnosing bacterial infections. In this protocol, we propose an electrochemical sandwich-type biosensor for highly sensitive detection of bacteria based on a bacterial imprinted polymer film (BIF) and metal-organic frameworks (MOF)-assisted redox recycling amplification. The BIF is formed in-situ through electropolymerization (EP) and template removal on the electrode surface, while aptamers are assembled on nanogold-modified MOF to create signal nanoprobes with target recognition ability. The BIF-modified electrode effectively captures the target bacteria and subsequently forms a sandwich structure through conjugation with signal nanoprobes, enabling efficient adsorption of methylene blue (MB). This facilitates the redox recycling of Fe(II) from the electroactive [Fe(CN)6]3-/4- in testing buffer assisted by MB, thereby generating a significantly amplified anodic current of [Fe(CN)6]3-/4- for precise quantitation. By utilizing the selective BIF interface and MOF-assisted redox recycling amplification, our method demonstrates excellent analytical performance with a low limit of detection (LOD) of 1 CFU mL−1, a broad detection range spanning from 10 to 108 CFU mL−1, and high selectivity. The feasibility of applying this approach for detecting bacteria in complex samples highlights its significant potential in areas related to food safety and public health. •A signal-on sandwich bacterial biosensor based on molecularly imprinted polymer was developed.•This study represented the initial report on enhancing the characteristic peak current of [Fe(CN)6]3−/4− assisted by MB.•This method offers an economical and sensitive sensing platform without the need for complicated sample pretreatment.