Ultrasensitive rapid detection of antibiotic resistance genes by electrochemical ratiometric genosensor based on 2D monolayer Ti3C2@AuNPs

• Published in: Biosensors & bioelectronics 2023-11, Vol.240, p.115643, Article 115643
• Main Authors: Sun, Pengcheng, Niu, Kai, Du, Haiying, Li, Ruixin, Chen, Jiping, Lu, Xianbo
• Format: Article
• Language: English
• Subjects: antibiotic resistance; Antibiotic resistance genes; biosensors; detection limit; Electrochemical sensor; electrochemistry; genes; Isothermal strand displacement polymerase reaction (ISDPR); nanogold; nanoparticles; nanosheets; pollutants; public health; quantitative analysis; rapid methods; Ratiometric biosensor; surface area; Titanium carbide (MXene)
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2023.115643

As an important emerging pollutant, antibiotic resistance genes (ARGs) monitoring is crucial to protect the ecological environment and public health, but its rapid and accurate detection is still a major challenge. In this study, a new single-labeled dual-signal output ratiometric electrochemical genosensor (E-DNA) was developed for the rapid and highly sensitive detection of ARGs using a synergistic signal amplification strategy of T3C2@Au nanoparticles (T3C2@AuNPs) and isothermal strand displacement polymerase reaction (ISDPR). Specially, two-dimensional monolayer T3C2 nanosheets loaded with uniformly gold nanoparticles were prepared and used as the sensing platform of the E-DNA sensor. Benefiting from excellent conductivity and large specific surface area of Ti3C2@AuNPs, the probe immobilization capacity of the E-DNA sensor is doubled, and electrochemical response signals of the E-DNA sensor were significantly improved. The proposed single-labeled dual-signal output ratiometric sensing strategy exhibits three to six times higher sensitivity for the sul2 gene than the single-signal sensing strategy, which significantly reduces cost meanwhile retaining the advantages of high sensitivity and reliability offered by conventional dual-labeled ratiometric sensors. Coupled with ISDPR amplification technology, the E-DNA sensor has a wider linear range from 10 fM to 10 nM and a limit of detection as low as 2.04 fM (S/N=3). More importantly, the E-DNA sensor demonstrates excellent specificity, good stability and reproducibility for target ARGs detection in real water samples. The proposed new sensing strategy provides a highly sensitive and versatile tool for the rapid and accurate quantitative analysis of various ARGs in environmental water samples.