A dual-mode aptasensor for foodborne pathogens detection using Pt, phenylboric acid and ferrocene modified Ti3C2 MXenes nanoprobe

Foodborne pathogens could result in serious health issues to public and thus some rapid analysis methods are urgent developed to monitor them. Herein, a dual-mode aptasensor based on electrochemical and colorimetric modes was constructed for the on-site detection of Vibrio parahaemolyticus (V.P) in shrimps as a model. A novel nanoprobe (PBA-Fc@Pt@MXenes) was developed to generate both electrochemical and colorimetric signals by modifying phenylboronic acid and ferrocene on Pt-MXenes nanocomposite. The nanoprobe exhibited both features of peroxidase mimic and specific recognition. Simultaneously, a V.P aptamer-functionalized electrode interface was fabricated to firstly specifically capture V.P, then conjugated with PBA-Fc@Pt@MXenes to form a sandwich complex. The complex could catalyze tetramethylbenzidine (TMB)-H2O2 to produce a visible signal, and generate electrochemical signal simultaneously. Under the optimal condition, the aptasensor could determine as low as 5 CFU mL(-1) V.P by electrochemical mode and 30 CFU mL(-1) V.P by colorimetric mode. These superior performances may be attributed to that the synergistic catalysis and conductive effects deriving from Pt and MXenes on the nanoprobe can significantly amplify the signals to improve detection sensitivity. In particular, the dual detection system could mutually verify to achieve high accuracy. The aptasensor could also be expanded to rapid analysis of other food-borne pathogens through changing the aptamer on the electrode.

Automated summary

In this study, a dual-mode aptasensor based on electrochemical and colorimetric modes was developed for the on-site detection of Vibrio parahaemolyticus in shrimps. The aptasensor showed high sensitivity and accuracy and could be extended to the rapid analysis of other foodborne pathogens.