Wavelength-Resolved Janus Biosensing Interface for Ratiometric Electrochemical Analysis

Abstract

The Janus interface, comprising multiple functional heterointerfaces with contrasting functionalities within a single interface, has recently garnered widespread research interest. Herein, a Janus biosensing interface is obtained via wavelength-resolved laser illumination. Deoxyribonucleic acid bridges the electrochemical probe of methylene blue (MB) and plasmonic gold nanoparticles (AuNPs), achieving a sensitive detection performance. MB shows differential electrochemical signals under front (I 532front ) and back (I 650back ) laser illumination at 532 and 650 nm, respectively, owing to the selective wavelength-resolved effect. Thus, the presence of a wavelength-resolved laser enabled the design of a biosensing interface with Janus properties. The change in the distance between MB and AuNPs induced by aflatoxin B1 (AFB1) indicates that a sensitive response of the Janus biosensing interface can be achieved. A ratiometric strategy is introduced to describe the electrochemical signals of the I 532front and I 650back for improved robustness. The obtained linear range is 0.0005−50 ng mL −1 , with a detection limit of 0.175 pg mL −1 . Our study demonstrated that the wavelength-resolved Janus interface enables an electrochemical biosensor with excellent sensitivity. This finding provides an efficient approach for improving biosensor performance.

A novel dual-model photoelectrochemical/electrochemical sensor based on Z-scheme TiO2 disks/methylene blue for kanamycin detection

“…3D, after embedding MB in the dsDNA, the MB/BSA/dsDNA/CS/TiO 2 /ITO electrode shows a large oxidation peak (curve a), because of the efficient electron transfer of the MB molecule. 43,44 However, in the presence of Kana, the oxidation peak current of MB is greatly reduced (curve b), due to Kana-induced digestion of dsDNA to release the MB molecule and the steric effect of Kana. These results shown in Fig.…”